- 21 Nov, 2018 40 commits
-
-
Roman Gushchin authored
commit a76cf1a4 upstream. Spock reported that commit 172b06c3 ("mm: slowly shrink slabs with a relatively small number of objects") leads to a regression on his setup: periodically the majority of the pagecache is evicted without an obvious reason, while before the change the amount of free memory was balancing around the watermark. The reason behind is that the mentioned above change created some minimal background pressure on the inode cache. The problem is that if an inode is considered to be reclaimed, all belonging pagecache page are stripped, no matter how many of them are there. So, if a huge multi-gigabyte file is cached in the memory, and the goal is to reclaim only few slab objects (unused inodes), we still can eventually evict all gigabytes of the pagecache at once. The workload described by Spock has few large non-mapped files in the pagecache, so it's especially noticeable. To solve the problem let's postpone the reclaim of inodes, which have more than 1 attached page. Let's wait until the pagecache pages will be evicted naturally by scanning the corresponding LRU lists, and only then reclaim the inode structure. Link: http://lkml.kernel.org/r/20181023164302.20436-1-guro@fb.comSigned-off-by: Roman Gushchin <guro@fb.com> Reported-by: Spock <dairinin@gmail.com> Tested-by: Spock <dairinin@gmail.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Rik van Riel <riel@surriel.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: <stable@vger.kernel.org> [4.19.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Ard Biesheuvel authored
commit 72a58a63 upstream. Commit: 24d7c494 ("efi/arm-stub: Round up FDT allocation to mapping size") increased the allocation size for the FDT image created by the stub to a fixed value of 2 MB, to simplify the former code that made several attempts with increasing values for the size. This is reasonable given that the allocation is of type EFI_LOADER_DATA, which is released to the kernel unless it is explicitly memblock_reserve()d by the early boot code. However, this allocation size leaked into the 'size' field of the FDT header metadata, and so the entire allocation remains occupied by the device tree binary, even if most of it is not used to store device tree information. So call fdt_pack() to shrink the FDT data structure to its minimum size after populating all the fields, so that the remaining memory is no longer wasted. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: <stable@vger.kernel.org> # v4.12+ Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Fixes: 24d7c494 ("efi/arm-stub: Round up FDT allocation to mapping size") Link: http://lkml.kernel.org/r/20181114175544.12860-4-ard.biesheuvel@linaro.orgSigned-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Vasily Averin authored
commit 873d7bcf upstream. Commit a2468cc9 ("swap: choose swap device according to numa node") changed 'avail_lists' field of 'struct swap_info_struct' to an array. In popular linux distros it increased size of swap_info_struct up to 40 Kbytes and now swap_info_struct allocation requires order-4 page. Switch to kvzmalloc allows to avoid unexpected allocation failures. Link: http://lkml.kernel.org/r/fc23172d-3c75-21e2-d551-8b1808cbe593@virtuozzo.com Fixes: a2468cc9 ("swap: choose swap device according to numa node") Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Acked-by: Aaron Lu <aaron.lu@intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Huang Ying <ying.huang@intel.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Mike Kravetz authored
commit 5e41540c upstream. This bug has been experienced several times by the Oracle DB team. The BUG is in remove_inode_hugepages() as follows: /* * If page is mapped, it was faulted in after being * unmapped in caller. Unmap (again) now after taking * the fault mutex. The mutex will prevent faults * until we finish removing the page. * * This race can only happen in the hole punch case. * Getting here in a truncate operation is a bug. */ if (unlikely(page_mapped(page))) { BUG_ON(truncate_op); In this case, the elevated map count is not the result of a race. Rather it was incorrectly incremented as the result of a bug in the huge pmd sharing code. Consider the following: - Process A maps a hugetlbfs file of sufficient size and alignment (PUD_SIZE) that a pmd page could be shared. - Process B maps the same hugetlbfs file with the same size and alignment such that a pmd page is shared. - Process B then calls mprotect() to change protections for the mapping with the shared pmd. As a result, the pmd is 'unshared'. - Process B then calls mprotect() again to chage protections for the mapping back to their original value. pmd remains unshared. - Process B then forks and process C is created. During the fork process, we do dup_mm -> dup_mmap -> copy_page_range to copy page tables. Copying page tables for hugetlb mappings is done in the routine copy_hugetlb_page_range. In copy_hugetlb_page_range(), the destination pte is obtained by: dst_pte = huge_pte_alloc(dst, addr, sz); If pmd sharing is possible, the returned pointer will be to a pte in an existing page table. In the situation above, process C could share with either process A or process B. Since process A is first in the list, the returned pte is a pointer to a pte in process A's page table. However, the check for pmd sharing in copy_hugetlb_page_range is: /* If the pagetables are shared don't copy or take references */ if (dst_pte == src_pte) continue; Since process C is sharing with process A instead of process B, the above test fails. The code in copy_hugetlb_page_range which follows assumes dst_pte points to a huge_pte_none pte. It copies the pte entry from src_pte to dst_pte and increments this map count of the associated page. This is how we end up with an elevated map count. To solve, check the dst_pte entry for huge_pte_none. If !none, this implies PMD sharing so do not copy. Link: http://lkml.kernel.org/r/20181105212315.14125-1-mike.kravetz@oracle.com Fixes: c5c99429 ("fix hugepages leak due to pagetable page sharing") Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Hugh Dickins <hughd@google.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Prakash Sangappa <prakash.sangappa@oracle.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Arnd Bergmann authored
commit 1c23b410 upstream. gcc-8 complains about the prototype for this function: lib/ubsan.c:432:1: error: ignoring attribute 'noreturn' in declaration of a built-in function '__ubsan_handle_builtin_unreachable' because it conflicts with attribute 'const' [-Werror=attributes] This is actually a GCC's bug. In GCC internals __ubsan_handle_builtin_unreachable() declared with both 'noreturn' and 'const' attributes instead of only 'noreturn': https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84210 Workaround this by removing the noreturn attribute. [aryabinin: add information about GCC bug in changelog] Link: http://lkml.kernel.org/r/20181107144516.4587-1-aryabinin@virtuozzo.comSigned-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Acked-by: Olof Johansson <olof@lixom.net> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Eric Biggers authored
commit f43f3995 upstream. All bytes of the NETLINK_CRYPTO report structures must be initialized, since they are copied to userspace. The change from strncpy() to strlcpy() broke this. As a minimal fix, change it back. Fixes: 4473710d ("crypto: user - Prepare for CRYPTO_MAX_ALG_NAME expansion") Cc: <stable@vger.kernel.org> # v4.12+ Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Diego Viola authored
commit 410b5c7b upstream. med_power_with_dipm still causes freezes after updating the firmware to the latest version (DXT04L5Q). Set model_rev to NULL and blacklist the device. Cc: stable@vger.kernel.org Signed-off-by: Diego Viola <diego.viola@gmail.com> Reviewed-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Andreas Gruenbacher authored
commit e7445ced upstream. The previous attempt to fix for metadata read-ahead during truncate was incorrect: for files with a height > 2 (1006989312 bytes with a block size of 4096 bytes), read-ahead requests were not being issued for some of the indirect blocks discovered while walking the metadata tree, leading to significant slow-downs when deleting large files. Fix that. In addition, only issue read-ahead requests in the first pass through the meta-data tree, while deallocating data blocks. Fixes: c3ce5aa9 ("gfs2: Fix metadata read-ahead during truncate") Cc: stable@vger.kernel.org # v4.16+ Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Andreas Gruenbacher authored
commit 10283ea5 upstream. gfs2_put_super calls gfs2_clear_rgrpd to destroy the gfs2_rgrpd objects attached to the resource group glocks. That function should release the buffers attached to the gfs2_bitmap objects (bi_bh), but the call to gfs2_rgrp_brelse for doing that is missing. When gfs2_releasepage later runs across these buffers which are still referenced, it refuses to free them. This causes the pages the buffers are attached to to remain referenced as well. With enough mount/unmount cycles, the system will eventually run out of memory. Fix this by adding the missing call to gfs2_rgrp_brelse in gfs2_clear_rgrpd. (Also fix a gfs2_rgrp_relse -> gfs2_rgrp_brelse typo in a comment.) Fixes: 39b0f1e9 ("GFS2: Don't brelse rgrp buffer_heads every allocation") Cc: stable@vger.kernel.org # v4.2+ Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Ondrej Mosnacek authored
commit c138325f upstream. selinux_sctp_bind_connect() must verify if the address buffer has sufficient length before accessing the 'sa_family' field. See __sctp_connect() for a similar check. The length of the whole address ('len') is already checked in the callees. Reported-by: Qian Cai <cai@gmx.us> Fixes: d452930f ("selinux: Add SCTP support") Cc: <stable@vger.kernel.org> # 4.17+ Cc: Richard Haines <richard_c_haines@btinternet.com> Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Tested-by: Qian Cai <cai@gmx.us> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Miklos Szeredi authored
commit 2d84a2d1 upstream. In current fuse_drop_waiting() implementation it's possible that fuse_wait_aborted() will not be woken up in the unlikely case that fuse_abort_conn() + fuse_wait_aborted() runs in between checking fc->connected and calling atomic_dec(&fc->num_waiting). Do the atomic_dec_and_test() unconditionally, which also provides the necessary barrier against reordering with the fc->connected check. The explicit smp_mb() in fuse_wait_aborted() is not actually needed, since the spin_unlock() in fuse_abort_conn() provides the necessary RELEASE barrier after resetting fc->connected. However, this is not a performance sensitive path, and adding the explicit barrier makes it easier to document. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Fixes: b8f95e5d ("fuse: umount should wait for all requests") Cc: <stable@vger.kernel.org> #v4.19 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Miklos Szeredi authored
commit 7fabaf30 upstream. fuse_request_send_notify_reply() may fail if the connection was reset for some reason (e.g. fs was unmounted). Don't leak request reference in this case. Besides leaking memory, this resulted in fc->num_waiting not being decremented and hence fuse_wait_aborted() left in a hanging and unkillable state. Fixes: 2d45ba38 ("fuse: add retrieve request") Fixes: b8f95e5d ("fuse: umount should wait for all requests") Reported-and-tested-by: syzbot+6339eda9cb4ebbc4c37b@syzkaller.appspotmail.com Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Cc: <stable@vger.kernel.org> #v2.6.36 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Lukas Czerner authored
commit ebacb812 upstream. In async IO blocking case the additional reference to the io is taken for it to survive fuse_aio_complete(). In non blocking case this additional reference is not needed, however we still reference io to figure out whether to wait for completion or not. This is wrong and will lead to use-after-free. Fix it by storing blocking information in separate variable. This was spotted by KASAN when running generic/208 fstest. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Reported-by: Zorro Lang <zlang@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Fixes: 744742d6 ("fuse: Add reference counting for fuse_io_priv") Cc: <stable@vger.kernel.org> # v4.6 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Maciej W. Rozycki authored
commit 7ce9a992 upstream. Fix an issue with the 32-bit range error path in `rtc_hctosys' where no error code is set and consequently the successful preceding call result from `rtc_read_time' is propagated to `rtc_hctosys_ret'. This in turn makes any subsequent call to `hctosys_show' incorrectly report in sysfs that the system time has been set from this RTC while it has not. Set the error to ERANGE then if we can't express the result due to an overflow. Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Fixes: b3a5ac42 ("rtc: hctosys: Ensure system time doesn't overflow time_t") Cc: stable@vger.kernel.org # 4.17+ Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Scott Mayhew authored
commit 01310bb7 upstream. Make sure we have a saved filehandle, otherwise we'll oops with a null pointer dereference in nfs4_preprocess_stateid_op(). Signed-off-by: Scott Mayhew <smayhew@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Trond Myklebust authored
commit 21a446cf upstream. If we exit the NFSv4 state manager due to a umount, then we can end up leaving the NFS4CLNT_MANAGER_RUNNING flag set. If another mount causes the nfs4_client to be rereferenced before it is destroyed, then we end up never being able to recover state. Fixes: 47c2199b ("NFSv4.1: Ensure state manager thread dies on last ...") Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Cc: stable@vger.kernel.org # v4.15+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Frank Sorenson authored
commit 5d7a5bcb upstream. When truncating the encode buffer, the page_ptr is getting advanced, causing the next page to be skipped while encoding. The page is still included in the response, so the response contains a page of bogus data. We need to adjust the page_ptr backwards to ensure we encode the next page into the correct place. We saw this triggered when concurrent directory modifications caused nfsd4_encode_direct_fattr() to return nfserr_noent, and the resulting call to xdr_truncate_encode() corrupted the READDIR reply. Signed-off-by: Frank Sorenson <sorenson@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Christophe Leroy authored
commit 568fb6f4 upstream. Since commit ad67b74d ("printk: hash addresses printed with %p"), all pointers printed with %p are printed with hashed addresses instead of real addresses in order to avoid leaking addresses in dmesg and syslog. But this applies to kdb too, with is unfortunate: Entering kdb (current=0x(ptrval), pid 329) due to Keyboard Entry kdb> ps 15 sleeping system daemon (state M) processes suppressed, use 'ps A' to see all. Task Addr Pid Parent [*] cpu State Thread Command 0x(ptrval) 329 328 1 0 R 0x(ptrval) *sh 0x(ptrval) 1 0 0 0 S 0x(ptrval) init 0x(ptrval) 3 2 0 0 D 0x(ptrval) rcu_gp 0x(ptrval) 4 2 0 0 D 0x(ptrval) rcu_par_gp 0x(ptrval) 5 2 0 0 D 0x(ptrval) kworker/0:0 0x(ptrval) 6 2 0 0 D 0x(ptrval) kworker/0:0H 0x(ptrval) 7 2 0 0 D 0x(ptrval) kworker/u2:0 0x(ptrval) 8 2 0 0 D 0x(ptrval) mm_percpu_wq 0x(ptrval) 10 2 0 0 D 0x(ptrval) rcu_preempt The whole purpose of kdb is to debug, and for debugging real addresses need to be known. In addition, data displayed by kdb doesn't go into dmesg. This patch replaces all %p by %px in kdb in order to display real addresses. Fixes: ad67b74d ("printk: hash addresses printed with %p") Cc: <stable@vger.kernel.org> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Christophe Leroy authored
commit dded2e15 upstream. On a powerpc 8xx, 'btc' fails as follows: Entering kdb (current=0x(ptrval), pid 282) due to Keyboard Entry kdb> btc btc: cpu status: Currently on cpu 0 Available cpus: 0 kdb_getarea: Bad address 0x0 when booting the kernel with 'debug_boot_weak_hash', it fails as well Entering kdb (current=0xba99ad80, pid 284) due to Keyboard Entry kdb> btc btc: cpu status: Currently on cpu 0 Available cpus: 0 kdb_getarea: Bad address 0xba99ad80 On other platforms, Oopses have been observed too, see https://github.com/linuxppc/linux/issues/139 This is due to btc calling 'btt' with %p pointer as an argument. This patch replaces %p by %px to get the real pointer value as expected by 'btt' Fixes: ad67b74d ("printk: hash addresses printed with %p") Cc: <stable@vger.kernel.org> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Ulf Hansson authored
commit 763f191a upstream. There's no point to register the cpuidle driver for the current CPU, when the initialization of the arch specific back-end data fails by returning -ENXIO. Instead, let's re-order the sequence to its original flow, by first trying to initialize the back-end part and then act accordingly on the returned error code. Additionally, let's print the error message, no matter of what error code that was returned. Fixes: a0d46a3d (ARM: cpuidle: Register per cpuidle device) Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: 4.19+ <stable@vger.kernel.org> # v4.19+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Dmitry V. Levin authored
commit aba11838 upstream. Consistently use types provided by <linux/types.h> via <drm/drm.h> to fix the following linux/kfd_ioctl.h userspace compilation errors: /usr/include/linux/kfd_ioctl.h:250:2: error: unknown type name 'uint32_t' uint32_t reset_type; /usr/include/linux/kfd_ioctl.h:251:2: error: unknown type name 'uint32_t' uint32_t reset_cause; /usr/include/linux/kfd_ioctl.h:252:2: error: unknown type name 'uint32_t' uint32_t memory_lost; /usr/include/linux/kfd_ioctl.h:253:2: error: unknown type name 'uint32_t' uint32_t gpu_id; Fixes: 0c119aba ("drm/amd: Add kfd ioctl defines for hw_exception event") Cc: <stable@vger.kernel.org> # v4.19 Signed-off-by: Dmitry V. Levin <ldv@altlinux.org> Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Benjamin Coddington authored
commit 1e9c75fb upstream. Since commit ff17fa56 ("d_invalidate(): unhash immediately") immediately unhashes the dentry, we'll never return the mountpoint in lookup_mountpoint(), which can lead to an unbreakable loop in d_invalidate(). I have reports of NFS clients getting into this condition after the server removes an export of an existing mount created through follow_automount(), but I suspect there are various other ways to produce this problem if we hunt down users of d_invalidate(). For example, it is possible to get into this state by using XFS' d_invalidate() call in xfs_vn_unlink(): truncate -s 100m img{1,2} mkfs.xfs -q -n version=ci img1 mkfs.xfs -q -n version=ci img2 mkdir -p /mnt/xfs mount img1 /mnt/xfs mkdir /mnt/xfs/sub1 mount img2 /mnt/xfs/sub1 cat > /mnt/xfs/sub1/foo & umount -l /mnt/xfs/sub1 mount img2 /mnt/xfs/sub1 mount --make-private /mnt/xfs mkdir /mnt/xfs/sub2 mount --move /mnt/xfs/sub1 /mnt/xfs/sub2 rmdir /mnt/xfs/sub1 Fix this by moving the check for an unlinked dentry out of the detach_mounts() path. Fixes: ff17fa56 ("d_invalidate(): unhash immediately") Cc: stable@vger.kernel.org Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Benjamin Coddington <bcodding@redhat.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Eric W. Biederman authored
commit 9c8e0a1b upstream. Timothy Baldwin <timbaldwin@fastmail.co.uk> wrote: > As per mount_namespaces(7) unprivileged users should not be able to look under mount points: > > Mounts that come as a single unit from more privileged mount are locked > together and may not be separated in a less privileged mount namespace. > > However they can: > > 1. Create a mount namespace. > 2. In the mount namespace open a file descriptor to the parent of a mount point. > 3. Destroy the mount namespace. > 4. Use the file descriptor to look under the mount point. > > I have reproduced this with Linux 4.16.18 and Linux 4.18-rc8. > > The setup: > > $ sudo sysctl kernel.unprivileged_userns_clone=1 > kernel.unprivileged_userns_clone = 1 > $ mkdir -p A/B/Secret > $ sudo mount -t tmpfs hide A/B > > > "Secret" is indeed hidden as expected: > > $ ls -lR A > A: > total 0 > drwxrwxrwt 2 root root 40 Feb 12 21:08 B > > A/B: > total 0 > > > The attack revealing "Secret": > > $ unshare -Umr sh -c "exec unshare -m ls -lR /proc/self/fd/4/ 4<A" > /proc/self/fd/4/: > total 0 > drwxr-xr-x 3 root root 60 Feb 12 21:08 B > > /proc/self/fd/4/B: > total 0 > drwxr-xr-x 2 root root 40 Feb 12 21:08 Secret > > /proc/self/fd/4/B/Secret: > total 0 I tracked this down to put_mnt_ns running passing UMOUNT_SYNC and disconnecting all of the mounts in a mount namespace. Fix this by factoring drop_mounts out of drop_collected_mounts and passing 0 instead of UMOUNT_SYNC. There are two possible behavior differences that result from this. - No longer setting UMOUNT_SYNC will no longer set MNT_SYNC_UMOUNT on the vfsmounts being unmounted. This effects the lazy rcu walk by kicking the walk out of rcu mode and forcing it to be a non-lazy walk. - No longer disconnecting locked mounts will keep some mounts around longer as they stay because the are locked to other mounts. There are only two users of drop_collected mounts: audit_tree.c and put_mnt_ns. In audit_tree.c the mounts are private and there are no rcu lazy walks only calls to iterate_mounts. So the changes should have no effect except for a small timing effect as the connected mounts are disconnected. In put_mnt_ns there may be references from process outside the mount namespace to the mounts. So the mounts remaining connected will be the bug fix that is needed. That rcu walks are allowed to continue appears not to be a problem especially as the rcu walk change was about an implementation detail not about semantics. Cc: stable@vger.kernel.org Fixes: 5ff9d8a6 ("vfs: Lock in place mounts from more privileged users") Reported-by: Timothy Baldwin <timbaldwin@fastmail.co.uk> Tested-by: Timothy Baldwin <timbaldwin@fastmail.co.uk> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Eric W. Biederman authored
commit df7342b2 upstream. Jonathan Calmels from NVIDIA reported that he's able to bypass the mount visibility security check in place in the Linux kernel by using a combination of the unbindable property along with the private mount propagation option to allow a unprivileged user to see a path which was purposefully hidden by the root user. Reproducer: # Hide a path to all users using a tmpfs root@castiana:~# mount -t tmpfs tmpfs /sys/devices/ root@castiana:~# # As an unprivileged user, unshare user namespace and mount namespace stgraber@castiana:~$ unshare -U -m -r # Confirm the path is still not accessible root@castiana:~# ls /sys/devices/ # Make /sys recursively unbindable and private root@castiana:~# mount --make-runbindable /sys root@castiana:~# mount --make-private /sys # Recursively bind-mount the rest of /sys over to /mnnt root@castiana:~# mount --rbind /sys/ /mnt # Access our hidden /sys/device as an unprivileged user root@castiana:~# ls /mnt/devices/ breakpoint cpu cstate_core cstate_pkg i915 intel_pt isa kprobe LNXSYSTM:00 msr pci0000:00 platform pnp0 power software system tracepoint uncore_arb uncore_cbox_0 uncore_cbox_1 uprobe virtual Solve this by teaching copy_tree to fail if a mount turns out to be both unbindable and locked. Cc: stable@vger.kernel.org Fixes: 5ff9d8a6 ("vfs: Lock in place mounts from more privileged users") Reported-by: Jonathan Calmels <jcalmels@nvidia.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Eric W. Biederman authored
commit 25d202ed upstream. It was recently pointed out that the one instance of testing MNT_LOCKED outside of the namespace_sem is in ksys_umount. Fix that by adding a test inside of do_umount with namespace_sem and the mount_lock held. As it helps to fail fails the existing test is maintained with an additional comment pointing out that it may be racy because the locks are not held. Cc: stable@vger.kernel.org Reported-by: Al Viro <viro@ZenIV.linux.org.uk> Fixes: 5ff9d8a6 ("vfs: Lock in place mounts from more privileged users") Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Vasily Averin authored
commit de59fae0 upstream. Fixes: dc6982ff ("ext4: refactor code to read directory blocks ...") Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org # 3.9 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Vasily Averin authored
commit 53692ec0 upstream. Fixes: de05ca85 ("ext4: move call to ext4_error() into ...") Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org # 4.17 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Vasily Averin authored
commit 6bdc9977 upstream. Fixes: 3f2571c1 ("ext4: factor out xattr moving") Fixes: 6dd4ee7c ("ext4: Expand extra_inodes space per ...") Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org # 2.6.23 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Vasily Averin authored
commit 45ae932d upstream. bs.bh was taken in previous ext4_xattr_block_find() call, it should be released before re-using Fixes: 7e01c8e5 ("ext3/4: fix uninitialized bs in ...") Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org # 2.6.26 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Vasily Averin authored
commit ecaaf408 upstream. Fixes: dec214d0 ("ext4: xattr inode deduplication") Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org # 4.13 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Vasily Averin authored
commit af18e35b upstream. Fixes: c8585c6f ("ext4: fix races between changing inode journal ...") Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org # 4.7 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Theodore Ts'o authored
commit 9e463084 upstream. Fixes: bfe0a5f4 ("ext4: add more mount time checks of the superblock") Reported-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org # 4.18 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Theodore Ts'o authored
commit 4f32c38b upstream. Fixes: b4097142 ("ext4: add error checking to calls to ...") Reported-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org # 2.6.38 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Vasily Averin authored
commit f348e224 upstream. Fixes: 117fff10 ("ext4: grow the s_flex_groups array as needed ...") Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org # 3.7 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Vasily Averin authored
commit feaf264c upstream. Fixes: d745a8c2 ("ext4: reduce contention on s_orphan_lock") Fixes: 6e3617e5 ("ext4: Handle non empty on-disk orphan link") Cc: Dmitry Monakhov <dmonakhov@gmail.com> Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org # 2.6.34 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Vasily Averin authored
commit a6758309 upstream. ext4_mark_iloc_dirty() callers expect that it releases iloc->bh even if it returns an error. Fixes: 0db1ff22 ("ext4: add shutdown bit and check for it") Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org # 4.11 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Vasily Averin authored
commit db6aee62 upstream. Fixes: 1c6bd717 ("ext4: convert file system to meta_bg if needed ...") Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org # 3.7 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Vasily Averin authored
commit eb6984fa upstream. According to Ted Ts'o ext4_getblk() called in ext4_xattr_inode_write() should not return bh = NULL The only time that bh could be NULL, then, would be in the case of something really going wrong; a programming error elsewhere (perhaps a wild pointer dereference) or I/O error causing on-disk file system corruption (although that would be highly unlikely given that we had *just* allocated the blocks and so the metadata blocks in question probably would still be in the cache). Fixes: e50e5129 ("ext4: xattr-in-inode support") Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org # 4.13 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Vasily Averin authored
commit 9e402893 upstream. Currently bh is set to NULL only during first iteration of for cycle, then this pointer is not cleared after end of using. Therefore rollback after errors can lead to extra brelse(bh) call, decrements bh counter and later trigger an unexpected warning in __brelse() Patch moves brelse() calls in body of cycle to exclude requirement of brelse() call in rollback. Fixes: 33afdcc5 ("ext4: add a function which sets up group blocks ...") Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org # 3.3+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Vasily Averin authored
commit 61a9c11e upstream. Fixes: 01f795f9 ("ext4: add online resizing support for meta_bg ...") Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org # 3.7 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-