- 05 Dec, 2015 25 commits
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Sasha Levin authored
commit 74e98eb0 upstream. There was no verification that an underlying transport exists when creating a connection, this would cause dereferencing a NULL ptr. It might happen on sockets that weren't properly bound before attempting to send a message, which will cause a NULL ptr deref: [135546.047719] kasan: GPF could be caused by NULL-ptr deref or user memory accessgeneral protection fault: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC KASAN [135546.051270] Modules linked in: [135546.051781] CPU: 4 PID: 15650 Comm: trinity-c4 Not tainted 4.2.0-next-20150902-sasha-00041-gbaa1222-dirty #2527 [135546.053217] task: ffff8800835bc000 ti: ffff8800bc708000 task.ti: ffff8800bc708000 [135546.054291] RIP: __rds_conn_create (net/rds/connection.c:194) [135546.055666] RSP: 0018:ffff8800bc70fab0 EFLAGS: 00010202 [135546.056457] RAX: dffffc0000000000 RBX: 0000000000000f2c RCX: ffff8800835bc000 [135546.057494] RDX: 0000000000000007 RSI: ffff8800835bccd8 RDI: 0000000000000038 [135546.058530] RBP: ffff8800bc70fb18 R08: 0000000000000001 R09: 0000000000000000 [135546.059556] R10: ffffed014d7a3a23 R11: ffffed014d7a3a21 R12: 0000000000000000 [135546.060614] R13: 0000000000000001 R14: ffff8801ec3d0000 R15: 0000000000000000 [135546.061668] FS: 00007faad4ffb700(0000) GS:ffff880252000000(0000) knlGS:0000000000000000 [135546.062836] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [135546.063682] CR2: 000000000000846a CR3: 000000009d137000 CR4: 00000000000006a0 [135546.064723] Stack: [135546.065048] ffffffffafe2055c ffffffffafe23fc1 ffffed00493097bf ffff8801ec3d0008 [135546.066247] 0000000000000000 00000000000000d0 0000000000000000 ac194a24c0586342 [135546.067438] 1ffff100178e1f78 ffff880320581b00 ffff8800bc70fdd0 ffff880320581b00 [135546.068629] Call Trace: [135546.069028] ? __rds_conn_create (include/linux/rcupdate.h:856 net/rds/connection.c:134) [135546.069989] ? rds_message_copy_from_user (net/rds/message.c:298) [135546.071021] rds_conn_create_outgoing (net/rds/connection.c:278) [135546.071981] rds_sendmsg (net/rds/send.c:1058) [135546.072858] ? perf_trace_lock (include/trace/events/lock.h:38) [135546.073744] ? lockdep_init (kernel/locking/lockdep.c:3298) [135546.074577] ? rds_send_drop_to (net/rds/send.c:976) [135546.075508] ? __might_fault (./arch/x86/include/asm/current.h:14 mm/memory.c:3795) [135546.076349] ? __might_fault (mm/memory.c:3795) [135546.077179] ? rds_send_drop_to (net/rds/send.c:976) [135546.078114] sock_sendmsg (net/socket.c:611 net/socket.c:620) [135546.078856] SYSC_sendto (net/socket.c:1657) [135546.079596] ? SYSC_connect (net/socket.c:1628) [135546.080510] ? trace_dump_stack (kernel/trace/trace.c:1926) [135546.081397] ? ring_buffer_unlock_commit (kernel/trace/ring_buffer.c:2479 kernel/trace/ring_buffer.c:2558 kernel/trace/ring_buffer.c:2674) [135546.082390] ? trace_buffer_unlock_commit (kernel/trace/trace.c:1749) [135546.083410] ? trace_event_raw_event_sys_enter (include/trace/events/syscalls.h:16) [135546.084481] ? do_audit_syscall_entry (include/trace/events/syscalls.h:16) [135546.085438] ? trace_buffer_unlock_commit (kernel/trace/trace.c:1749) [135546.085515] rds_ib_laddr_check(): addr 36.74.25.172 ret -99 node type -1 Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> (cherry picked from commit 987ad6ee) Signed-off-by: Willy Tarreau <w@1wt.eu>
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Andy Lutomirski authored
commit fc57a7c6 upstream. PARAVIRT_ADJUST_EXCEPTION_FRAME generates this code (using nmi as an example, trimmed for readability): ff 15 00 00 00 00 callq *0x0(%rip) # 2796 <nmi+0x6> 2792: R_X86_64_PC32 pv_irq_ops+0x2c That's a call through a function pointer to regular C function that does nothing on native boots, but that function isn't protected against kprobes, isn't marked notrace, and is certainly not guaranteed to preserve any registers if the compiler is feeling perverse. This is bad news for a CLBR_NONE operation. Of course, if everything works correctly, once paravirt ops are patched, it gets nopped out, but what if we hit this code before paravirt ops are patched in? This can potentially cause breakage that is very difficult to debug. A more subtle failure is possible here, too: if _paravirt_nop uses the stack at all (even just to push RBP), it will overwrite the "NMI executing" variable if it's called in the NMI prologue. The Xen case, perhaps surprisingly, is fine, because it's already written in asm. Fix all of the cases that default to paravirt_nop (including adjust_exception_frame) with a big hammer: replace paravirt_nop with an asm function that is just a ret instruction. The Xen case may have other problems, so document them. This is part of a fix for some random crashes that Sasha saw. Reported-and-tested-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Andy Lutomirski <luto@kernel.org> Link: http://lkml.kernel.org/r/8f5d2ba295f9d73751c33d97fda03e0495d9ade0.1442791737.git.luto@kernel.orgSigned-off-by: Thomas Gleixner <tglx@linutronix.de> [bwh: Backported to 3.2: adjust filename, context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> (cherry picked from commit 81fbc9a5) Signed-off-by: Willy Tarreau <w@1wt.eu>
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Hin-Tak Leung authored
commit b4cc0efe upstream. Fix B-tree corruption when a new record is inserted at position 0 in the node in hfs_brec_insert(). This is an identical change to the corresponding hfs b-tree code to Sergei Antonov's "hfsplus: fix B-tree corruption after insertion at position 0", to keep similar code paths in the hfs and hfsplus drivers in sync, where appropriate. Signed-off-by: Hin-Tak Leung <htl10@users.sourceforge.net> Cc: Sergei Antonov <saproj@gmail.com> Cc: Joe Perches <joe@perches.com> Reviewed-by: Vyacheslav Dubeyko <slava@dubeyko.com> Cc: Anton Altaparmakov <anton@tuxera.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> (cherry picked from commit d46a3490) Signed-off-by: Willy Tarreau <w@1wt.eu>
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Hin-Tak Leung authored
commit 7cb74be6 upstream. Pages looked up by __hfs_bnode_create() (called by hfs_bnode_create() and hfs_bnode_find() for finding or creating pages corresponding to an inode) are immediately kmap()'ed and used (both read and write) and kunmap()'ed, and should not be page_cache_release()'ed until hfs_bnode_free(). This patch fixes a problem I first saw in July 2012: merely running "du" on a large hfsplus-mounted directory a few times on a reasonably loaded system would get the hfsplus driver all confused and complaining about B-tree inconsistencies, and generates a "BUG: Bad page state". Most recently, I can generate this problem on up-to-date Fedora 22 with shipped kernel 4.0.5, by running "du /" (="/" + "/home" + "/mnt" + other smaller mounts) and "du /mnt" simultaneously on two windows, where /mnt is a lightly-used QEMU VM image of the full Mac OS X 10.9: $ df -i / /home /mnt Filesystem Inodes IUsed IFree IUse% Mounted on /dev/mapper/fedora-root 3276800 551665 2725135 17% / /dev/mapper/fedora-home 52879360 716221 52163139 2% /home /dev/nbd0p2 4294967295 1387818 4293579477 1% /mnt After applying the patch, I was able to run "du /" (60+ times) and "du /mnt" (150+ times) continuously and simultaneously for 6+ hours. There are many reports of the hfsplus driver getting confused under load and generating "BUG: Bad page state" or other similar issues over the years. [1] The unpatched code [2] has always been wrong since it entered the kernel tree. The only reason why it gets away with it is that the kmap/memcpy/kunmap follow very quickly after the page_cache_release() so the kernel has not had a chance to reuse the memory for something else, most of the time. The current RW driver appears to have followed the design and development of the earlier read-only hfsplus driver [3], where-by version 0.1 (Dec 2001) had a B-tree node-centric approach to read_cache_page()/page_cache_release() per bnode_get()/bnode_put(), migrating towards version 0.2 (June 2002) of caching and releasing pages per inode extents. When the current RW code first entered the kernel [2] in 2005, there was an REF_PAGES conditional (and "//" commented out code) to switch between B-node centric paging to inode-centric paging. There was a mistake with the direction of one of the REF_PAGES conditionals in __hfs_bnode_create(). In a subsequent "remove debug code" commit [4], the read_cache_page()/page_cache_release() per bnode_get()/bnode_put() were removed, but a page_cache_release() was mistakenly left in (propagating the "REF_PAGES <-> !REF_PAGE" mistake), and the commented-out page_cache_release() in bnode_release() (which should be spanned by !REF_PAGES) was never enabled. References: [1]: Michael Fox, Apr 2013 http://www.spinics.net/lists/linux-fsdevel/msg63807.html ("hfsplus volume suddenly inaccessable after 'hfs: recoff %d too large'") Sasha Levin, Feb 2015 http://lkml.org/lkml/2015/2/20/85 ("use after free") https://bugs.launchpad.net/ubuntu/+source/linux/+bug/740814 https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1027887 https://bugzilla.kernel.org/show_bug.cgi?id=42342 https://bugzilla.kernel.org/show_bug.cgi?id=63841 https://bugzilla.kernel.org/show_bug.cgi?id=78761 [2]: http://git.kernel.org/cgit/linux/kernel/git/tglx/history.git/commit/\ fs/hfs/bnode.c?id=d1081202 commit d1081202 Author: Andrew Morton <akpm@osdl.org> Date: Wed Feb 25 16:17:36 2004 -0800 [PATCH] HFS rewrite http://git.kernel.org/cgit/linux/kernel/git/tglx/history.git/commit/\ fs/hfsplus/bnode.c?id=91556682 commit 91556682 Author: Andrew Morton <akpm@osdl.org> Date: Wed Feb 25 16:17:48 2004 -0800 [PATCH] HFS+ support [3]: http://sourceforge.net/projects/linux-hfsplus/ http://sourceforge.net/projects/linux-hfsplus/files/Linux%202.4.x%20patch/hfsplus%200.1/ http://sourceforge.net/projects/linux-hfsplus/files/Linux%202.4.x%20patch/hfsplus%200.2/ http://linux-hfsplus.cvs.sourceforge.net/viewvc/linux-hfsplus/linux/\ fs/hfsplus/bnode.c?r1=1.4&r2=1.5 Date: Thu Jun 6 09:45:14 2002 +0000 Use buffer cache instead of page cache in bnode.c. Cache inode extents. [4]: http://git.kernel.org/cgit/linux/kernel/git/\ stable/linux-stable.git/commit/?id=a5e3985f commit a5e3985f Author: Roman Zippel <zippel@linux-m68k.org> Date: Tue Sep 6 15:18:47 2005 -0700 [PATCH] hfs: remove debug code Signed-off-by: Hin-Tak Leung <htl10@users.sourceforge.net> Signed-off-by: Sergei Antonov <saproj@gmail.com> Reviewed-by: Anton Altaparmakov <anton@tuxera.com> Reported-by: Sasha Levin <sasha.levin@oracle.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@infradead.org> Cc: Vyacheslav Dubeyko <slava@dubeyko.com> Cc: Sougata Santra <sougata@tuxera.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> (cherry picked from commit dd04e674) Signed-off-by: Willy Tarreau <w@1wt.eu>
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Konstantin Khlebnikov authored
commit 1c90308e upstream. This patch makes pagemap readable for normal users and hides physical addresses from them. For some use-cases PFN isn't required at all. See http://lkml.kernel.org/r/1425935472-17949-1-git-send-email-kirill@shutemov.name Fixes: ab676b7d ("pagemap: do not leak physical addresses to non-privileged userspace") Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Reviewed-by: Mark Williamson <mwilliamson@undo-software.com> Tested-by: Mark Williamson <mwilliamson@undo-software.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> [bwh: Backported to 3.2: - Add the same check in the places where we look up a PFN - Add struct pagemapread * parameters where necessary - Open-code file_ns_capable() - Delete pagemap_open() entirely, as it would always return 0] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> (cherry picked from commit b1fb185f) [wt: adjusted context, no pagemap_hugetlb_range() in 2.6.32, needs cred argument to security_capable(), tested OK ] Signed-off-by: Willy Tarreau <w@1wt.eu>
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Chris Wright authored
commit 6037b715 upstream. Expand security_capable() to include cred, so that it can be usable in a wider range of call sites. Signed-off-by: Chris Wright <chrisw@sous-sol.org> Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: James Morris <jmorris@namei.org> [wt: needed by next patch only] Signed-off-by: Willy Tarreau <w@1wt.eu>
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Takashi Iwai authored
commit eb38f3a4 upstream. We've got bug reports showing the old systemd-logind (at least system-210) aborting unexpectedly, and this turned out to be because of an invalid error code from close() call to evdev devices. close() is supposed to return only either EINTR or EBADFD, while the device returned ENODEV. logind was overreacting to it and decided to kill itself when an unexpected error code was received. What a tragedy. The bad error code comes from flush fops, and actually evdev_flush() returns ENODEV when device is disconnected or client's access to it is revoked. But in these cases the fact that flush did not actually happen is not an error, but rather normal behavior. For non-disconnected devices result of flush is also not that interesting as there is no potential of data loss and even if it fails application has no way of handling the error. Because of that we are better off always returning success from evdev_flush(). Also returning EINTR from flush()/close() is discouraged (as it is not clear how application should handle this error), so let's stop taking evdev->mutex interruptibly. Bugzilla: http://bugzilla.suse.com/show_bug.cgi?id=939834Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> [bwh: Backported to 3.2: there's no revoked flag to test] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> (cherry picked from commit a6706174) Signed-off-by: Willy Tarreau <w@1wt.eu>
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Trond Myklebust authored
commit 0c78789e upstream. In case the reconnection attempt fails. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> [bwh: Backported to 3.2: add local variable xprt] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> (cherry picked from commit 9434e485) Signed-off-by: Willy Tarreau <w@1wt.eu>
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Jan Kara authored
commit ffeecc52 upstream. struct xfs_attr_leafblock contains 'entries' array which is declared with size 1 altough it can in fact contain much more entries. Since this array is followed by further struct members, gcc (at least in version 4.8.3) thinks that the array has the fixed size of 1 element and thus may optimize away all accesses beyond the end of array resulting in non-working code. This problem was only observed with userspace code in xfsprogs, however it's better to be safe in kernel as well and have matching kernel and xfsprogs definitions. Signed-off-by: Jan Kara <jack@suse.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com> [bwh: Backported to 3.2: adjust filename] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> (cherry picked from commit 86cbc007) Signed-off-by: Willy Tarreau <w@1wt.eu>
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Paul Bolle authored
commit fe2b5921 upstream. wf_unregister_client() increments the client count when a client unregisters. That is obviously incorrect. Decrement that client count instead. Fixes: 75722d39 ("[PATCH] ppc64: Thermal control for SMU based machines") Signed-off-by: Paul Bolle <pebolle@tiscali.nl> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> (cherry picked from commit 48c46d4a) Signed-off-by: Willy Tarreau <w@1wt.eu>
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Masahiro Yamada authored
commit 64526370 upstream. Currently, devres_get() passes devres_free() the pointer to devres, but devres_free() should be given with the pointer to resource data. Fixes: 9ac7849e ("devres: device resource management") Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> (cherry picked from commit ebc0ae5a) Signed-off-by: Willy Tarreau <w@1wt.eu>
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Herton R. Krzesinski authored
commit 602b8593 upstream. The current semaphore code allows a potential use after free: in exit_sem we may free the task's sem_undo_list while there is still another task looping through the same semaphore set and cleaning the sem_undo list at freeary function (the task called IPC_RMID for the same semaphore set). For example, with a test program [1] running which keeps forking a lot of processes (which then do a semop call with SEM_UNDO flag), and with the parent right after removing the semaphore set with IPC_RMID, and a kernel built with CONFIG_SLAB, CONFIG_SLAB_DEBUG and CONFIG_DEBUG_SPINLOCK, you can easily see something like the following in the kernel log: Slab corruption (Not tainted): kmalloc-64 start=ffff88003b45c1c0, len=64 000: 6b 6b 6b 6b 6b 6b 6b 6b 00 6b 6b 6b 6b 6b 6b 6b kkkkkkkk.kkkkkkk 010: ff ff ff ff 6b 6b 6b 6b ff ff ff ff ff ff ff ff ....kkkk........ Prev obj: start=ffff88003b45c180, len=64 000: 00 00 00 00 ad 4e ad de ff ff ff ff 5a 5a 5a 5a .....N......ZZZZ 010: ff ff ff ff ff ff ff ff c0 fb 01 37 00 88 ff ff ...........7.... Next obj: start=ffff88003b45c200, len=64 000: 00 00 00 00 ad 4e ad de ff ff ff ff 5a 5a 5a 5a .....N......ZZZZ 010: ff ff ff ff ff ff ff ff 68 29 a7 3c 00 88 ff ff ........h).<.... BUG: spinlock wrong CPU on CPU#2, test/18028 general protection fault: 0000 [#1] SMP Modules linked in: 8021q mrp garp stp llc nf_conntrack_ipv4 nf_defrag_ipv4 ip6t_REJECT nf_reject_ipv6 nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables binfmt_misc ppdev input_leds joydev parport_pc parport floppy serio_raw virtio_balloon virtio_rng virtio_console virtio_net iosf_mbi crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcspkr qxl ttm drm_kms_helper drm snd_hda_codec_generic i2c_piix4 snd_hda_intel snd_hda_codec snd_hda_core snd_hwdep snd_seq snd_seq_device snd_pcm snd_timer snd soundcore crc32c_intel virtio_pci virtio_ring virtio pata_acpi ata_generic [last unloaded: speedstep_lib] CPU: 2 PID: 18028 Comm: test Not tainted 4.2.0-rc5+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.8.1-20150318_183358- 04/01/2014 RIP: spin_dump+0x53/0xc0 Call Trace: spin_bug+0x30/0x40 do_raw_spin_unlock+0x71/0xa0 _raw_spin_unlock+0xe/0x10 freeary+0x82/0x2a0 ? _raw_spin_lock+0xe/0x10 semctl_down.clone.0+0xce/0x160 ? __do_page_fault+0x19a/0x430 ? __audit_syscall_entry+0xa8/0x100 SyS_semctl+0x236/0x2c0 ? syscall_trace_leave+0xde/0x130 entry_SYSCALL_64_fastpath+0x12/0x71 Code: 8b 80 88 03 00 00 48 8d 88 60 05 00 00 48 c7 c7 a0 2c a4 81 31 c0 65 8b 15 eb 40 f3 7e e8 08 31 68 00 4d 85 e4 44 8b 4b 08 74 5e <45> 8b 84 24 88 03 00 00 49 8d 8c 24 60 05 00 00 8b 53 04 48 89 RIP [<ffffffff810d6053>] spin_dump+0x53/0xc0 RSP <ffff88003750fd68> ---[ end trace 783ebb76612867a0 ]--- NMI watchdog: BUG: soft lockup - CPU#3 stuck for 22s! [test:18053] Modules linked in: 8021q mrp garp stp llc nf_conntrack_ipv4 nf_defrag_ipv4 ip6t_REJECT nf_reject_ipv6 nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables binfmt_misc ppdev input_leds joydev parport_pc parport floppy serio_raw virtio_balloon virtio_rng virtio_console virtio_net iosf_mbi crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcspkr qxl ttm drm_kms_helper drm snd_hda_codec_generic i2c_piix4 snd_hda_intel snd_hda_codec snd_hda_core snd_hwdep snd_seq snd_seq_device snd_pcm snd_timer snd soundcore crc32c_intel virtio_pci virtio_ring virtio pata_acpi ata_generic [last unloaded: speedstep_lib] CPU: 3 PID: 18053 Comm: test Tainted: G D 4.2.0-rc5+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.8.1-20150318_183358- 04/01/2014 RIP: native_read_tsc+0x0/0x20 Call Trace: ? delay_tsc+0x40/0x70 __delay+0xf/0x20 do_raw_spin_lock+0x96/0x140 _raw_spin_lock+0xe/0x10 sem_lock_and_putref+0x11/0x70 SYSC_semtimedop+0x7bf/0x960 ? handle_mm_fault+0xbf6/0x1880 ? dequeue_task_fair+0x79/0x4a0 ? __do_page_fault+0x19a/0x430 ? kfree_debugcheck+0x16/0x40 ? __do_page_fault+0x19a/0x430 ? __audit_syscall_entry+0xa8/0x100 ? do_audit_syscall_entry+0x66/0x70 ? syscall_trace_enter_phase1+0x139/0x160 SyS_semtimedop+0xe/0x10 SyS_semop+0x10/0x20 entry_SYSCALL_64_fastpath+0x12/0x71 Code: 47 10 83 e8 01 85 c0 89 47 10 75 08 65 48 89 3d 1f 74 ff 7e c9 c3 0f 1f 44 00 00 55 48 89 e5 e8 87 17 04 00 66 90 c9 c3 0f 1f 00 <55> 48 89 e5 0f 31 89 c1 48 89 d0 48 c1 e0 20 89 c9 48 09 c8 c9 Kernel panic - not syncing: softlockup: hung tasks I wasn't able to trigger any badness on a recent kernel without the proper config debugs enabled, however I have softlockup reports on some kernel versions, in the semaphore code, which are similar as above (the scenario is seen on some servers running IBM DB2 which uses semaphore syscalls). The patch here fixes the race against freeary, by acquiring or waiting on the sem_undo_list lock as necessary (exit_sem can race with freeary, while freeary sets un->semid to -1 and removes the same sem_undo from list_proc or when it removes the last sem_undo). After the patch I'm unable to reproduce the problem using the test case [1]. [1] Test case used below: #include <stdio.h> #include <sys/types.h> #include <sys/ipc.h> #include <sys/sem.h> #include <sys/wait.h> #include <stdlib.h> #include <time.h> #include <unistd.h> #include <errno.h> #define NSEM 1 #define NSET 5 int sid[NSET]; void thread() { struct sembuf op; int s; uid_t pid = getuid(); s = rand() % NSET; op.sem_num = pid % NSEM; op.sem_op = 1; op.sem_flg = SEM_UNDO; semop(sid[s], &op, 1); exit(EXIT_SUCCESS); } void create_set() { int i, j; pid_t p; union { int val; struct semid_ds *buf; unsigned short int *array; struct seminfo *__buf; } un; /* Create and initialize semaphore set */ for (i = 0; i < NSET; i++) { sid[i] = semget(IPC_PRIVATE , NSEM, 0644 | IPC_CREAT); if (sid[i] < 0) { perror("semget"); exit(EXIT_FAILURE); } } un.val = 0; for (i = 0; i < NSET; i++) { for (j = 0; j < NSEM; j++) { if (semctl(sid[i], j, SETVAL, un) < 0) perror("semctl"); } } /* Launch threads that operate on semaphore set */ for (i = 0; i < NSEM * NSET * NSET; i++) { p = fork(); if (p < 0) perror("fork"); if (p == 0) thread(); } /* Free semaphore set */ for (i = 0; i < NSET; i++) { if (semctl(sid[i], NSEM, IPC_RMID)) perror("IPC_RMID"); } /* Wait for forked processes to exit */ while (wait(NULL)) { if (errno == ECHILD) break; }; } int main(int argc, char **argv) { pid_t p; srand(time(NULL)); while (1) { p = fork(); if (p < 0) { perror("fork"); exit(EXIT_FAILURE); } if (p == 0) { create_set(); goto end; } /* Wait for forked processes to exit */ while (wait(NULL)) { if (errno == ECHILD) break; }; } end: return 0; } [akpm@linux-foundation.org: use normal comment layout] Signed-off-by: Herton R. Krzesinski <herton@redhat.com> Acked-by: Manfred Spraul <manfred@colorfullife.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Rafael Aquini <aquini@redhat.com> CC: Aristeu Rozanski <aris@redhat.com> Cc: David Jeffery <djeffery@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> (cherry picked from commit a1c4fb80) Signed-off-by: Willy Tarreau <w@1wt.eu>
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Herbert Xu authored
commit a0a2a660 upstream. The commit 738ac1eb ("net: Clone skb before setting peeked flag") introduced a use-after-free bug in skb_recv_datagram. This is because skb_set_peeked may create a new skb and free the existing one. As it stands the caller will continue to use the old freed skb. This patch fixes it by making skb_set_peeked return the new skb (or the old one if unchanged). Fixes: 738ac1eb ("net: Clone skb before setting peeked flag") Reported-by: Brenden Blanco <bblanco@plumgrid.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Tested-by: Brenden Blanco <bblanco@plumgrid.com> Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> (cherry picked from commit e553622c) Signed-off-by: Willy Tarreau <w@1wt.eu>
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Herbert Xu authored
commit 738ac1eb upstream. Shared skbs must not be modified and this is crucial for broadcast and/or multicast paths where we use it as an optimisation to avoid unnecessary cloning. The function skb_recv_datagram breaks this rule by setting peeked without cloning the skb first. This causes funky races which leads to double-free. This patch fixes this by cloning the skb and replacing the skb in the list when setting skb->peeked. Fixes: a59322be ("[UDP]: Only increment counter on first peek/recv") Reported-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> (cherry picked from commit 72e6f068) [wt: adjusted context for 2.6.32. Introduces a bug, see next commit] Signed-off-by: Willy Tarreau <w@1wt.eu>
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Dan Carpenter authored
commit 468b732b upstream. "len" is a signed integer. We check that len is not negative, so it goes from zero to INT_MAX. PAGE_SIZE is unsigned long so the comparison is type promoted to unsigned long. ULONG_MAX - 4095 is a higher than INT_MAX so the condition can never be true. I don't know if this is harmful but it seems safe to limit "len" to INT_MAX - 4095. Fixes: a8c879a7 ('RDS: Info and stats') Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> (cherry picked from commit f3a66bdc) Signed-off-by: Willy Tarreau <w@1wt.eu>
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Mathias Nyman authored
commit 7895086a upstream. We need to check that a TRB is part of the current segment before calculating its DMA address. Previously a ring segment didn't use a full memory page, and every new ring segment got a new memory page, so the off by one error in checking the upper bound was never seen. Now that we use a full memory page, 256 TRBs (4096 bytes), the off by one didn't catch the case when a TRB was the first element of the next segment. This is triggered if the virtual memory pages for a ring segment are next to each in increasing order where the ring buffer wraps around and causes errors like: [ 106.398223] xhci_hcd 0000:00:14.0: ERROR Transfer event TRB DMA ptr not part of current TD ep_index 0 comp_code 1 [ 106.398230] xhci_hcd 0000:00:14.0: Looking for event-dma fffd3000 trb-start fffd4fd0 trb-end fffd5000 seg-start fffd4000 seg-end fffd4ff0 The trb-end address is one outside the end-seg address. Tested-by: Arkadiusz Miśkiewicz <arekm@maven.pl> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> (cherry picked from commit 6e3ae625) Signed-off-by: Willy Tarreau <w@1wt.eu>
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Linus Torvalds authored
commit b9a53227 upstream. As reported by Dmitry Vyukov, we really shouldn't do ipc_addid() before having initialized the IPC object state. Yes, we initialize the IPC object in a locked state, but with all the lockless RCU lookup work, that IPC object lock no longer means that the state cannot be seen. We already did this for the IPC semaphore code (see commit e8577d1f: "ipc/sem.c: fully initialize sem_array before making it visible") but we clearly forgot about msg and shm. Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: Davidlohr Bueso <dbueso@suse.de> Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> [bwh: Backported to 2.6.32: - Adjust context - The error path being moved looks a little different] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Willy Tarreau <w@1wt.eu>
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Manfred Spraul authored
commit e8577d1f upstream. ipc_addid() makes a new ipc identifier visible to everyone. New objects start as locked, so that the caller can complete the initialization after the call. Within struct sem_array, at least sma->sem_base and sma->sem_nsems are accessed without any locks, therefore this approach doesn't work. Thus: Move the ipc_addid() to the end of the initialization. Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Reported-by: Rik van Riel <riel@redhat.com> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Davidlohr Bueso <dave@stgolabs.net> Acked-by: Rafael Aquini <aquini@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> [bwh: Backported to 2.6.32: - Adjust context - The error path being moved looks a little different] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Willy Tarreau <w@1wt.eu>
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Johan Hovold authored
commit cbb4be65 upstream. Fix potential null-pointer dereference at probe by making sure that the required endpoints are present. The whiteheat driver assumes there are at least five pairs of bulk endpoints, of which the final pair is used for the "command port". An attempt to bind to an interface with fewer bulk endpoints would currently lead to an oops. Fixes CVE-2015-5257. Reported-by: Moein Ghasemzadeh <moein@istuary.com> Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Willy Tarreau <w@1wt.eu>
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Jason Wang authored
commit 48900cb6 upstream. virtio declares support for NETIF_F_FRAGLIST, but assumes that there are at most MAX_SKB_FRAGS + 2 fragments which isn't always true with a fraglist. A longer fraglist in the skb will make the call to skb_to_sgvec overflow the sg array, leading to memory corruption. Drop NETIF_F_FRAGLIST so we only get what we can handle. Cc: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Jason Wang <jasowang@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> [bwh: Backported to 2.6.32: there's only a single features field] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Willy Tarreau <w@1wt.eu>
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Marcelo Leitner authored
commit 77751427 upstream. Currently we don't check if the new MTU is valid or not and this allows one to configure a smaller than minimum allowed by RFCs or even bigger than interface own MTU, which is a problem as it may lead to packet drops. If you have a daemon like NetworkManager running, this may be exploited by remote attackers by forging RA packets with an invalid MTU, possibly leading to a DoS. (NetworkManager currently only validates for values too small, but not for too big ones.) The fix is just to make sure the new value is valid. That is, between IPV6_MIN_MTU and interface's MTU. Note that similar check is already performed at ndisc_router_discovery(), for when kernel itself parses the RA. Signed-off-by: Marcelo Ricardo Leitner <mleitner@redhat.com> Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: David S. Miller <davem@davemloft.net> [bwh: Backported to 2.6.32: - Add a strategy for the sysctl as we don't get a default strategy - Adjust context, spacing] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Willy Tarreau <w@1wt.eu>
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Benjamin Randazzo authored
commit b6878d9e upstream. In drivers/md/md.c get_bitmap_file() uses kmalloc() for creating a mdu_bitmap_file_t called "file". 5769 file = kmalloc(sizeof(*file), GFP_NOIO); 5770 if (!file) 5771 return -ENOMEM; This structure is copied to user space at the end of the function. 5786 if (err == 0 && 5787 copy_to_user(arg, file, sizeof(*file))) 5788 err = -EFAULT But if bitmap is disabled only the first byte of "file" is initialized with zero, so it's possible to read some bytes (up to 4095) of kernel space memory from user space. This is an information leak. 5775 /* bitmap disabled, zero the first byte and copy out */ 5776 if (!mddev->bitmap_info.file) 5777 file->pathname[0] = '\0'; Signed-off-by: Benjamin Randazzo <benjamin@randazzo.fr> Signed-off-by: NeilBrown <neilb@suse.com> [bwh: Backported to 2.6.32: patch both possible allocation calls] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Willy Tarreau <w@1wt.eu>
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Olga Kornievskaia authored
commit a41cbe86 upstream. A test case is as the description says: open(foobar, O_WRONLY); sleep() --> reboot the server close(foobar) The bug is because in nfs4state.c in nfs4_reclaim_open_state() a few line before going to restart, there is clear_bit(NFS4CLNT_RECLAIM_NOGRACE, &state->flags). NFS4CLNT_RECLAIM_NOGRACE is a flag for the client states not open owner states. Value of NFS4CLNT_RECLAIM_NOGRACE is 4 which is the value of NFS_O_WRONLY_STATE in nfs4_state->flags. So clearing it wipes out state and when we go to close it, “call_close” doesn’t get set as state flag is not set and CLOSE doesn’t go on the wire. Signed-off-by: Olga Kornievskaia <aglo@umich.edu> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
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Eric W. Biederman authored
commit 397d425d upstream. In rare cases a directory can be renamed out from under a bind mount. In those cases without special handling it becomes possible to walk up the directory tree to the root dentry of the filesystem and down from the root dentry to every other file or directory on the filesystem. Like division by zero .. from an unconnected path can not be given a useful semantic as there is no predicting at which path component the code will realize it is unconnected. We certainly can not match the current behavior as the current behavior is a security hole. Therefore when encounting .. when following an unconnected path return -ENOENT. - Add a function path_connected to verify path->dentry is reachable from path->mnt.mnt_root. AKA to validate that rename did not do something nasty to the bind mount. To avoid races path_connected must be called after following a path component to it's next path component. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Willy Tarreau <w@1wt.eu>
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Eric W. Biederman authored
commit cde93be4 upstream. A rename can result in a dentry that by walking up d_parent will never reach it's mnt_root. For lack of a better term I call this an escaped path. prepend_path is called by four different functions __d_path, d_absolute_path, d_path, and getcwd. __d_path only wants to see paths are connected to the root it passes in. So __d_path needs prepend_path to return an error. d_absolute_path similarly wants to see paths that are connected to some root. Escaped paths are not connected to any mnt_root so d_absolute_path needs prepend_path to return an error greater than 1. So escaped paths will be treated like paths on lazily unmounted mounts. getcwd needs to prepend "(unreachable)" so getcwd also needs prepend_path to return an error. d_path is the interesting hold out. d_path just wants to print something, and does not care about the weird cases. Which raises the question what should be printed? Given that <escaped_path>/<anything> should result in -ENOENT I believe it is desirable for escaped paths to be printed as empty paths. As there are not really any meaninful path components when considered from the perspective of a mount tree. So tweak prepend_path to return an empty path with an new error code of 3 when it encounters an escaped path. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> [bwh: For 2.6.32, implement the "(unreachable)" string in __d_path()] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Willy Tarreau <w@1wt.eu>
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- 18 Sep, 2015 15 commits
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Willy Tarreau authored
Signed-off-by: Willy Tarreau <w@1wt.eu>
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David S. Miller authored
commit 6ac3f664 upstream. Like ipv4, just return xfrm6_rcv_spi()'s return value directly. Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Willy Tarreau <w@1wt.eu>
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Dr. David Alan Gilbert authored
commit d07a74a5 upstream. Hi, On the latest tree my compiler has started giving the warning: drivers/dma/dmatest.c:575:28: warning: the omitted middle operand in ?: will always be ?true?, suggest explicit middle operand [-Wparentheses] The following patch fixes the missing middle clause with the same fix that Nicolas Ferre used in the similar clauses. (There seems to have been a race between him fixing that and the extra clause going in a little later). I don't actually know the dmatest code/structures, nor do I own any hardware to test it on (assuming it needs a DMA engine); but this patch builds, the existing code is almost certainly wrong and the fix is the same as the corresponding lines above it. (WTH is x=y?:z legal C anyway?) Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Reported-by: Paul Gortmaker <paul.gortmaker@windriver.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
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Wang Weidong authored
commit 965cdea8 upstream. Check the return value of request_module during dccp_probe initialisation, bail out if that call fails. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: Wang Weidong <wangweidong1@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Willy Tarreau <w@1wt.eu>
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David S. Miller authored
commit d984e619 upstream. Commit 1386be55 ("dccp: fix auto-loading of dccp(_probe)") fixed a bug but created a new compiler warning: net/dccp/probe.c: In function ‘dccpprobe_init’: net/dccp/probe.c:166:2: warning: the omitted middle operand in ?: will always be ‘true’, suggest explicit middle operand [-Wparentheses] try_then_request_module() is built for situations where the "existence" test is some lookup function that returns a non-NULL object on success, and with a reference count of some kind held. Here we're looking for a success return of zero from the jprobe registry. Instead of fighting the way try_then_request_module() works, simply open code what we want to happen in a local helper function. Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Willy Tarreau <w@1wt.eu>
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Gerrit Renker authored
commit 1386be55 upstream. This fixes commit (38ff3e6b) ("dccp_probe: Fix module load dependencies between dccp and dccp_probe", from 15 Jan). It fixes the construction of the first argument of try_then_request_module(), where only valid return codes from the first argument should be returned. What we do now is assign the result of register_jprobe() to ret, without the side effect of the comparison. Acked-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Willy Tarreau <w@1wt.eu>
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Andy Lutomirski authored
commit aa1acff3 upstream. The update_va_mapping hypercall can fail if the VA isn't present in the guest's page tables. Under certain loads, this can result in an OOPS when the target address is in unpopulated vmap space. While we're at it, add comments to help explain what's going on. This isn't a great long-term fix. This code should probably be changed to use something like set_memory_ro. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andrew Cooper <andrew.cooper3@citrix.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: David Vrabel <dvrabel@cantab.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jan Beulich <jbeulich@suse.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: security@kernel.org <security@kernel.org> Cc: xen-devel <xen-devel@lists.xen.org> Link: http://lkml.kernel.org/r/0b0e55b995cda11e7829f140b833ef932fcabe3a.1438291540.git.luto@kernel.orgSigned-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> (cherry picked from commit b48d6a72) Signed-off-by: Willy Tarreau <w@1wt.eu>
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Mikulas Patocka authored
commit d531be2c upstream. I have a ST4000DM000 disk. If Linux is booted while the disk is spun down, the command that sets transfer mode causes the disk to spin up. The spin-up takes longer than the default 5s timeout, so the command fails and timeout is reported. Fix this by increasing the timeout to 15s, which is enough for the disk to spin up. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> (cherry picked from commit d6ded324) Signed-off-by: Willy Tarreau <w@1wt.eu>
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Heiko Carstens authored
commit e47994dd upstream. The sfpc inline assembly within execve_tail() may incorrectly set bits 28-31 of the sfpc instruction to a value which is not zero. These bits however are currently unused and therefore should be zero so we won't get surprised if these bits will be used in the future. Therefore remove the second operand from the inline assembly. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> (cherry picked from commit b411a8a3) Signed-off-by: Willy Tarreau <w@1wt.eu>
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Kirill A. Shutemov authored
commit 6b7339f4 upstream. Reading page fault handler code I've noticed that under right circumstances kernel would map anonymous pages into file mappings: if the VMA doesn't have vm_ops->fault() and the VMA wasn't fully populated on ->mmap(), kernel would handle page fault to not populated pte with do_anonymous_page(). Let's change page fault handler to use do_anonymous_page() only on anonymous VMA (->vm_ops == NULL) and make sure that the VMA is not shared. For file mappings without vm_ops->fault() or shred VMA without vm_ops, page fault on pte_none() entry would lead to SIGBUS. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Willy Tarreau <w@1wt.eu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> (cherry picked from commit e2506476) Signed-off-by: Willy Tarreau <w@1wt.eu>
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Miklos Szeredi authored
commit 0ad0b325 upstream. fc->release is called from fuse_conn_put() which was used in the error cleanup before fc->release was initialized. [Jeremiah Mahler <jmmahler@gmail.com>: assign fc->release after calling fuse_conn_init(fc) instead of before.] Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Fixes: a325f9b9 ("fuse: update fuse_conn_init() and separate out fuse_conn_kill()") Signed-off-by: Ben Hutchings <ben@decadent.org.uk> (cherry picked from commit 1a713f98) Signed-off-by: Willy Tarreau <w@1wt.eu>
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Steven Rostedt (Red Hat) authored
commit 6b88f44e upstream. While debugging a WARN_ON() for filtering, I found that it is possible for the filter string to be referenced after its end. With the filter: # echo '>' > /sys/kernel/debug/events/ext4/ext4_truncate_exit/filter The filter_parse() function can call infix_get_op() which calls infix_advance() that updates the infix filter pointers for the cnt and tail without checking if the filter is already at the end, which will put the cnt to zero and the tail beyond the end. The loop then calls infix_next() that has ps->infix.cnt--; return ps->infix.string[ps->infix.tail++]; The cnt will now be below zero, and the tail that is returned is already passed the end of the filter string. So far the allocation of the filter string usually has some buffer that is zeroed out, but if the filter string is of the exact size of the allocated buffer there's no guarantee that the charater after the nul terminating character will be zero. Luckily, only root can write to the filter. Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> (cherry picked from commit 7cc2315e) Signed-off-by: Willy Tarreau <w@1wt.eu>
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Steven Rostedt (Red Hat) authored
commit b4875bbe upstream. When testing the fix for the trace filter, I could not come up with a scenario where the operand count goes below zero, so I added a WARN_ON_ONCE(cnt < 0) to the logic. But there is legitimate case that it can happen (although the filter would be wrong). # echo '>' > /sys/kernel/debug/events/ext4/ext4_truncate_exit/filter That is, a single operation without any operands will hit the path where the WARN_ON_ONCE() can trigger. Although this is harmless, and the filter is reported as a error. But instead of spitting out a warning to the kernel dmesg, just fail nicely and report it via the proper channels. Link: http://lkml.kernel.org/r/558C6082.90608@oracle.comReported-by: Vince Weaver <vincent.weaver@maine.edu> Reported-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> (cherry picked from commit b43dd359) Signed-off-by: Willy Tarreau <w@1wt.eu>
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Catalin Marinas authored
commit c5f3b1a5 upstream. The kmemleak scanning thread can run for minutes. Callbacks like kmemleak_free() are allowed during this time, the race being taken care of by the object->lock spinlock. Such lock also prevents a memory block from being freed or unmapped while it is being scanned by blocking the kmemleak_free() -> ... -> __delete_object() function until the lock is released in scan_object(). When a kmemleak error occurs (e.g. it fails to allocate its metadata), kmemleak_enabled is set and __delete_object() is no longer called on freed objects. If kmemleak_scan is running at the same time, kmemleak_free() no longer waits for the object scanning to complete, allowing the corresponding memory block to be freed or unmapped (in the case of vfree()). This leads to kmemleak_scan potentially triggering a page fault. This patch separates the kmemleak_free() enabling/disabling from the overall kmemleak_enabled nob so that we can defer the disabling of the object freeing tracking until the scanning thread completed. The kmemleak_free_part() is deliberately ignored by this patch since this is only called during boot before the scanning thread started. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Reported-by: Vignesh Radhakrishnan <vigneshr@codeaurora.org> Tested-by: Vignesh Radhakrishnan <vigneshr@codeaurora.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> [bwh: Backported to 3.2: - Adjust context - Drop changes to kmemleak_free_percpu()] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> (cherry picked from commit 3bc68ffc) Signed-off-by: Willy Tarreau <w@1wt.eu>
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Ralf Baechle authored
commit d496f784 upstream. A ROSE socket doesn't necessarily always have a neighbour pointer so check if the neighbour pointer is valid before dereferencing it. Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Tested-by: Bernard Pidoux <f6bvp@free.fr> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> (cherry picked from commit 8bbe4f44) Signed-off-by: Willy Tarreau <w@1wt.eu>
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