- 20 Nov, 2016 40 commits
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Matt Fleming authored
commit 080fe0b7 upstream. While the Intel PMU monitors the LLC when perf enables the HW_CACHE_REFERENCES and HW_CACHE_MISSES events, these events monitor L1 instruction cache fetches (0x0080) and instruction cache misses (0x0081) on the AMD PMU. This is extremely confusing when monitoring the same workload across Intel and AMD machines, since parameters like, $ perf stat -e cache-references,cache-misses measure completely different things. Instead, make the AMD PMU measure instruction/data cache and TLB fill requests to the L2 and instruction/data cache and TLB misses in the L2 when HW_CACHE_REFERENCES and HW_CACHE_MISSES are enabled, respectively. That way the events measure unified caches on both platforms. Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1472044328-21302-1-git-send-email-matt@codeblueprint.co.ukSigned-off-by: Ingo Molnar <mingo@kernel.org> [bwh: Backported to 3.16: - Drop KVM PMU changes - Adjust filename] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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Al Viro authored
commit 8630c322 upstream. really ugly, but apparently avr32 compilers turns access_ok() into something so bad that they want it in assembler. Left that way, zeroing added in inline wrapper. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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Al Viro authored
commit e98b9e37 upstream. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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Al Viro authored
commit d0cf3851 upstream. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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Al Viro authored
commit c90a3bc5 upstream. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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Al Viro authored
commit 8f035983 upstream. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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Al Viro authored
commit 917400ce upstream. Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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Al Viro authored
commit 6e050503 upstream. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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Al Viro authored
commit c6852389 upstream. It could be done in exception-handling bits in __get_user_b() et.al., but the surgery involved would take more knowledge of sh64 details than I have or _want_ to have. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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Al Viro authored
commit b615e3c7 upstream. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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Al Viro authored
commit c2f18fa4 upstream. * should zero on any failure * __get_user() should use __copy_from_user(), not copy_from_user() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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Al Viro authored
commit fd2d2b19 upstream. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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Al Viro authored
commit 22426465 upstream. should clear on access_ok() failures. Also remove the useless range truncation logics. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> [bwh: Backported to 3.16: no calls to check_object_size()] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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Al Viro authored
commit aace880f upstream. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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Al Viro authored
commit acb2505d upstream. ... that should zero on faults. Also remove the <censored> helpful logics wrt range truncation copied from ppc32. Where it had ever been needed only in case of copy_from_user() *and* had not been merged into the mainline until a month after the need had disappeared. A decade before openrisc went into mainline, I might add... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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Al Viro authored
commit ae7cc577 upstream. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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Al Viro authored
commit 43403eab upstream. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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Al Viro authored
commit e69d7005 upstream. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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Vineet Gupta authored
commit 05d9d0b9 upstream. Al reported potential issue with ARC get_user() as it wasn't clearing out destination pointer in case of fault due to bad address etc. Verified using following | { | u32 bogus1 = 0xdeadbeef; | u64 bogus2 = 0xdead; | int rc1, rc2; | | pr_info("Orig values %x %llx\n", bogus1, bogus2); | rc1 = get_user(bogus1, (u32 __user *)0x40000000); | rc2 = get_user(bogus2, (u64 __user *)0x50000000); | pr_info("access %d %d, new values %x %llx\n", | rc1, rc2, bogus1, bogus2); | } | [ARCLinux]# insmod /mnt/kernel-module/qtn.ko | Orig values deadbeef dead | access -14 -14, new values 0 0 Reported-by: Al Viro <viro@ZenIV.linux.org.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-snps-arc@lists.infradead.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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Al Viro authored
commit 8ae95ed4 upstream. Acked-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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Al Viro authored
commit a5e541f7 upstream. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> [bwh: Backported to 3.16: no calls to check_object_size()] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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Al Viro authored
commit f35c1e06 upstream. It's -EFAULT, not -1 (and contrary to the comment in there, __strnlen_user() can return 0 - on faults). Acked-by: Richard Kuo <rkuo@codeaurora.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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Al Viro authored
commit 3b8767a8 upstream. It should check access_ok(). Otherwise a bunch of places turn into trivially exploitable rootholes. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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Al Viro authored
commit eb47e029 upstream. * copy_from_user() on access_ok() failure ought to zero the destination * none of those primitives should skip the access_ok() check in case of small constant size. Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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Al Viro authored
commit 9ad18b75 upstream. both for access_ok() failures and for faults halfway through Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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Johannes Berg authored
commit ad5987b4 upstream. Due to an apparent copy/paste bug, the number of counters for the beacon configuration were checked twice, instead of checking the number of probe response counters. Fix this to check the number of probe response counters before parsing those. Fixes: 9a774c78 ("cfg80211: Support multiple CSA counters") Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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Matt Redfearn authored
commit 951c39cd upstream. If the paravirt machine is compiles without CONFIG_SMP, the following linker error occurs arch/mips/kernel/head.o: In function `kernel_entry': (.ref.text+0x10): undefined reference to `smp_bootstrap' due to the kernel entry macro always including SMP startup code. Wrap this code in CONFIG_SMP to fix the error. Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/14212/Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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Ard Biesheuvel authored
commit 2db34e78 upstream. The AES-CTR glue code avoids calling into the blkcipher API for the tail portion of the walk, by comparing the remainder of walk.nbytes modulo AES_BLOCK_SIZE with the residual nbytes, and jumping straight into the tail processing block if they are equal. This tail processing block checks whether nbytes != 0, and does nothing otherwise. However, in case of an allocation failure in the blkcipher layer, we may enter this code with walk.nbytes == 0, while nbytes > 0. In this case, we should not dereference the source and destination pointers, since they may be NULL. So instead of checking for nbytes != 0, check for (walk.nbytes % AES_BLOCK_SIZE) != 0, which implies the former in non-error conditions. Fixes: 49788fe2 ("arm64/crypto: AES-ECB/CBC/CTR/XTS using ARMv8 NEON and Crypto Extensions") Reported-by: xiakaixu <xiakaixu@huawei.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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Herbert Xu authored
commit acdb04d0 upstream. When we need to allocate a temporary blkcipher_walk_next and it fails, the code is supposed to take the slow path of processing the data block by block. However, due to an unrelated change we instead end up dereferencing the NULL pointer. This patch fixes it by moving the unrelated bsize setting out of the way so that we enter the slow path as inteded. Fixes: 7607bd8f ("[CRYPTO] blkcipher: Added blkcipher_walk_virt_block") Reported-by: xiakaixu <xiakaixu@huawei.com> Reported-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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Russell King authored
commit 06dfe5cc upstream. SA1111 PCMCIA was broken when PCMCIA switched to using dev_pm_ops for the PCMCIA socket class. PCMCIA used to handle suspend/resume via the socket hosting device, which happened at normal device suspend/resume time. However, the referenced commit changed this: much of the resume now happens much earlier, in the noirq resume handler of dev_pm_ops. However, on SA1111, the PCMCIA device is not accessible as the SA1111 has not been resumed at _noirq time. It's slightly worse than that, because the SA1111 has already been put to sleep at _noirq time, so suspend doesn't work properly. Fix this by converting the core SA1111 code to use dev_pm_ops as well, and performing its own suspend/resume at noirq time. This fixes these errors in the kernel log: pcmcia_socket pcmcia_socket0: time out after reset pcmcia_socket pcmcia_socket1: time out after reset and the resulting lack of PCMCIA cards after a S2RAM cycle. Fixes: d7646f76 ("pcmcia: use dev_pm_ops for class pcmcia_socket_class") Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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Daniele Palmas authored
commit f190fd92 upstream. This patch adds support for Infineon flashloader 0x8087/0x0801. The flashloader is used in Telit LE940B modem family with Telit flashing application. Signed-off-by: Daniele Palmas <dnlplm@gmail.com> Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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Trond Myklebust authored
commit b519d408 upstream. Ensure that we conform to the algorithm described in RFC5661, section 18.36.4 for when to bump the sequence id. In essence we do it for all cases except when the RPC call timed out, or in case of the server returning NFS4ERR_DELAY or NFS4ERR_STALE_CLIENTID. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> [bwh: Backported to 3.16: - Add the 'out' label - Adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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Karl Beldan authored
commit f6d7c1b5 upstream. This fixes subpage writes when using 4-bit HW ECC. There has been numerous reports about ECC errors with devices using this driver for a while. Also the 4-bit ECC has been reported as broken with subpages in [1] and with 16 bits NANDs in the driver and in mach* board files both in mainline and in the vendor BSPs. What I saw with 4-bit ECC on a 16bits NAND (on an LCDK) which got me to try reinitializing the ECC engine: - R/W on whole pages properly generates/checks RS code - try writing the 1st subpage only of a blank page, the subpage is well written and the RS code properly generated, re-reading the same page the HW detects some ECC error, reading the same page again no ECC error is detected Note that the ECC engine is already reinitialized in the 1-bit case. Tested on my LCDK with UBI+UBIFS using subpages. This could potentially get rid of the issue workarounded in [1]. [1] 28c015a9 ("mtd: davinci-nand: disable subpage write for keystone-nand") Fixes: 6a4123e5 ("mtd: nand: davinci_nand, 4-bit ECC for smallpage") Signed-off-by: Karl Beldan <kbeldan@baylibre.com> Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com> Signed-off-by: Brian Norris <computersforpeace@gmail.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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Al Viro authored
commit 2545e5da upstream. ... in all cases, including the failing access_ok() Note that some architectures using asm-generic/uaccess.h have __copy_from_user() not zeroing the tail on failure halfway through. This variant works either way. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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Al Viro authored
commit 2561d309 upstream. it should clear the destination even when access_ok() fails. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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Will Deacon authored
commit 872c63fb upstream. smp_mb__before_spinlock() is intended to upgrade a spin_lock() operation to a full barrier, such that prior stores are ordered with respect to loads and stores occuring inside the critical section. Unfortunately, the core code defines the barrier as smp_wmb(), which is insufficient to provide the required ordering guarantees when used in conjunction with our load-acquire-based spinlock implementation. This patch overrides the arm64 definition of smp_mb__before_spinlock() to map to a full smp_mb(). Cc: Peter Zijlstra <peterz@infradead.org> Reported-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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Suzuki K Poulose authored
commit 293f2936 upstream. On arm/arm64, we depend on the kvm_unmap_hva* callbacks (via mmu_notifiers::invalidate_*) to unmap the stage2 pagetables when the userspace buffer gets unmapped. However, when the Hypervisor process exits without explicit unmap of the guest buffers, the only notifier we get is kvm_arch_flush_shadow_all() (via mmu_notifier::release ) which does nothing on arm. Later this causes us to access pages that were already released [via exit_mmap() -> unmap_vmas()] when we actually get to unmap the stage2 pagetable [via kvm_arch_destroy_vm() -> kvm_free_stage2_pgd()]. This triggers crashes with CONFIG_DEBUG_PAGEALLOC, which unmaps any free'd pages from the linear map. [ 757.644120] Unable to handle kernel paging request at virtual address ffff800661e00000 [ 757.652046] pgd = ffff20000b1a2000 [ 757.655471] [ffff800661e00000] *pgd=00000047fffe3003, *pud=00000047fcd8c003, *pmd=00000047fcc7c003, *pte=00e8004661e00712 [ 757.666492] Internal error: Oops: 96000147 [#3] PREEMPT SMP [ 757.672041] Modules linked in: [ 757.675100] CPU: 7 PID: 3630 Comm: qemu-system-aar Tainted: G D 4.8.0-rc1 #3 [ 757.683240] Hardware name: AppliedMicro X-Gene Mustang Board/X-Gene Mustang Board, BIOS 3.06.15 Aug 19 2016 [ 757.692938] task: ffff80069cdd3580 task.stack: ffff8006adb7c000 [ 757.698840] PC is at __flush_dcache_area+0x1c/0x40 [ 757.703613] LR is at kvm_flush_dcache_pmd+0x60/0x70 [ 757.708469] pc : [<ffff20000809dbdc>] lr : [<ffff2000080b4a70>] pstate: 20000145 ... [ 758.357249] [<ffff20000809dbdc>] __flush_dcache_area+0x1c/0x40 [ 758.363059] [<ffff2000080b6748>] unmap_stage2_range+0x458/0x5f0 [ 758.368954] [<ffff2000080b708c>] kvm_free_stage2_pgd+0x34/0x60 [ 758.374761] [<ffff2000080b2280>] kvm_arch_destroy_vm+0x20/0x68 [ 758.380570] [<ffff2000080aa330>] kvm_put_kvm+0x210/0x358 [ 758.385860] [<ffff2000080aa524>] kvm_vm_release+0x2c/0x40 [ 758.391239] [<ffff2000082ad234>] __fput+0x114/0x2e8 [ 758.396096] [<ffff2000082ad46c>] ____fput+0xc/0x18 [ 758.400869] [<ffff200008104658>] task_work_run+0x108/0x138 [ 758.406332] [<ffff2000080dc8ec>] do_exit+0x48c/0x10e8 [ 758.411363] [<ffff2000080dd5fc>] do_group_exit+0x6c/0x130 [ 758.416739] [<ffff2000080ed924>] get_signal+0x284/0xa18 [ 758.421943] [<ffff20000808a098>] do_signal+0x158/0x860 [ 758.427060] [<ffff20000808aad4>] do_notify_resume+0x6c/0x88 [ 758.432608] [<ffff200008083624>] work_pending+0x10/0x14 [ 758.437812] Code: 9ac32042 8b010001 d1000443 8a230000 (d50b7e20) This patch fixes the issue by moving the kvm_free_stage2_pgd() to kvm_arch_flush_shadow_all(). Tested-by: Itaru Kitayama <itaru.kitayama@riken.jp> Reported-by: Itaru Kitayama <itaru.kitayama@riken.jp> Reported-by: James Morse <james.morse@arm.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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Mathias Krause authored
commit 2f30ea50 upstream. When we fail to attach the security context in xfrm_state_construct() we'll return 0 as error value which, in turn, will wrongly claim success to userland when, in fact, we won't be adding / updating the XFRM state. This is a regression introduced by commit fd21150a ("[XFRM] netlink: Inline attach_encap_tmpl(), attach_sec_ctx(), and attach_one_addr()"). Fix it by propagating the error returned by security_xfrm_state_alloc() in this case. Fixes: fd21150a ("[XFRM] netlink: Inline attach_encap_tmpl()...") Signed-off-by: Mathias Krause <minipli@googlemail.com> Cc: Thomas Graf <tgraf@suug.ch> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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Takashi Iwai authored
commit 816f318b upstream. When a seq-virmidi driver is initialized, it registers a rawmidi instance with its callback to create an associated seq kernel client. Currently it's done throughly in rawmidi's register_mutex context. Recently it was found that this may lead to a deadlock another rawmidi device that is being attached with the sequencer is accessed, as both open with the same register_mutex. This was actually triggered by syzkaller, as Dmitry Vyukov reported: ====================================================== [ INFO: possible circular locking dependency detected ] 4.8.0-rc1+ #11 Not tainted ------------------------------------------------------- syz-executor/7154 is trying to acquire lock: (register_mutex#5){+.+.+.}, at: [<ffffffff84fd6d4b>] snd_rawmidi_kernel_open+0x4b/0x260 sound/core/rawmidi.c:341 but task is already holding lock: (&grp->list_mutex){++++.+}, at: [<ffffffff850138bb>] check_and_subscribe_port+0x5b/0x5c0 sound/core/seq/seq_ports.c:495 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&grp->list_mutex){++++.+}: [<ffffffff8147a3a8>] lock_acquire+0x208/0x430 kernel/locking/lockdep.c:3746 [<ffffffff863f6199>] down_read+0x49/0xc0 kernel/locking/rwsem.c:22 [< inline >] deliver_to_subscribers sound/core/seq/seq_clientmgr.c:681 [<ffffffff85005c5e>] snd_seq_deliver_event+0x35e/0x890 sound/core/seq/seq_clientmgr.c:822 [<ffffffff85006e96>] > snd_seq_kernel_client_dispatch+0x126/0x170 sound/core/seq/seq_clientmgr.c:2418 [<ffffffff85012c52>] snd_seq_system_broadcast+0xb2/0xf0 sound/core/seq/seq_system.c:101 [<ffffffff84fff70a>] snd_seq_create_kernel_client+0x24a/0x330 sound/core/seq/seq_clientmgr.c:2297 [< inline >] snd_virmidi_dev_attach_seq sound/core/seq/seq_virmidi.c:383 [<ffffffff8502d29f>] snd_virmidi_dev_register+0x29f/0x750 sound/core/seq/seq_virmidi.c:450 [<ffffffff84fd208c>] snd_rawmidi_dev_register+0x30c/0xd40 sound/core/rawmidi.c:1645 [<ffffffff84f816d3>] __snd_device_register.part.0+0x63/0xc0 sound/core/device.c:164 [< inline >] __snd_device_register sound/core/device.c:162 [<ffffffff84f8235d>] snd_device_register_all+0xad/0x110 sound/core/device.c:212 [<ffffffff84f7546f>] snd_card_register+0xef/0x6c0 sound/core/init.c:749 [<ffffffff85040b7f>] snd_virmidi_probe+0x3ef/0x590 sound/drivers/virmidi.c:123 [<ffffffff833ebf7b>] platform_drv_probe+0x8b/0x170 drivers/base/platform.c:564 ...... -> #0 (register_mutex#5){+.+.+.}: [< inline >] check_prev_add kernel/locking/lockdep.c:1829 [< inline >] check_prevs_add kernel/locking/lockdep.c:1939 [< inline >] validate_chain kernel/locking/lockdep.c:2266 [<ffffffff814791f4>] __lock_acquire+0x4d44/0x4d80 kernel/locking/lockdep.c:3335 [<ffffffff8147a3a8>] lock_acquire+0x208/0x430 kernel/locking/lockdep.c:3746 [< inline >] __mutex_lock_common kernel/locking/mutex.c:521 [<ffffffff863f0ef1>] mutex_lock_nested+0xb1/0xa20 kernel/locking/mutex.c:621 [<ffffffff84fd6d4b>] snd_rawmidi_kernel_open+0x4b/0x260 sound/core/rawmidi.c:341 [<ffffffff8502e7c7>] midisynth_subscribe+0xf7/0x350 sound/core/seq/seq_midi.c:188 [< inline >] subscribe_port sound/core/seq/seq_ports.c:427 [<ffffffff85013cc7>] check_and_subscribe_port+0x467/0x5c0 sound/core/seq/seq_ports.c:510 [<ffffffff85015da9>] snd_seq_port_connect+0x2c9/0x500 sound/core/seq/seq_ports.c:579 [<ffffffff850079b8>] snd_seq_ioctl_subscribe_port+0x1d8/0x2b0 sound/core/seq/seq_clientmgr.c:1480 [<ffffffff84ffe9e4>] snd_seq_do_ioctl+0x184/0x1e0 sound/core/seq/seq_clientmgr.c:2225 [<ffffffff84ffeae8>] snd_seq_kernel_client_ctl+0xa8/0x110 sound/core/seq/seq_clientmgr.c:2440 [<ffffffff85027664>] snd_seq_oss_midi_open+0x3b4/0x610 sound/core/seq/oss/seq_oss_midi.c:375 [<ffffffff85023d67>] snd_seq_oss_synth_setup_midi+0x107/0x4c0 sound/core/seq/oss/seq_oss_synth.c:281 [<ffffffff8501b0a8>] snd_seq_oss_open+0x748/0x8d0 sound/core/seq/oss/seq_oss_init.c:274 [<ffffffff85019d8a>] odev_open+0x6a/0x90 sound/core/seq/oss/seq_oss.c:138 [<ffffffff84f7040f>] soundcore_open+0x30f/0x640 sound/sound_core.c:639 ...... other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&grp->list_mutex); lock(register_mutex#5); lock(&grp->list_mutex); lock(register_mutex#5); *** DEADLOCK *** ====================================================== The fix is to simply move the registration parts in snd_rawmidi_dev_register() to the outside of the register_mutex lock. The lock is needed only to manage the linked list, and it's not necessarily to cover the whole initialization process. Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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Takashi Iwai authored
commit 9f8a7658 upstream. When a user timer instance is continued without the explicit start beforehand, the system gets eventually zero-division error like: divide error: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN CPU: 1 PID: 27320 Comm: syz-executor Not tainted 4.8.0-rc3-next-20160825+ #8 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 task: ffff88003c9b2280 task.stack: ffff880027280000 RIP: 0010:[<ffffffff858e1a6c>] [< inline >] ktime_divns include/linux/ktime.h:195 RIP: 0010:[<ffffffff858e1a6c>] [<ffffffff858e1a6c>] snd_hrtimer_callback+0x1bc/0x3c0 sound/core/hrtimer.c:62 Call Trace: <IRQ> [< inline >] __run_hrtimer kernel/time/hrtimer.c:1238 [<ffffffff81504335>] __hrtimer_run_queues+0x325/0xe70 kernel/time/hrtimer.c:1302 [<ffffffff81506ceb>] hrtimer_interrupt+0x18b/0x420 kernel/time/hrtimer.c:1336 [<ffffffff8126d8df>] local_apic_timer_interrupt+0x6f/0xe0 arch/x86/kernel/apic/apic.c:933 [<ffffffff86e13056>] smp_apic_timer_interrupt+0x76/0xa0 arch/x86/kernel/apic/apic.c:957 [<ffffffff86e1210c>] apic_timer_interrupt+0x8c/0xa0 arch/x86/entry/entry_64.S:487 <EOI> ..... Although a similar issue was spotted and a fix patch was merged in commit [6b760bb2: ALSA: timer: fix division by zero after SNDRV_TIMER_IOCTL_CONTINUE], it seems covering only a part of iceberg. In this patch, we fix the issue a bit more drastically. Basically the continue of an uninitialized timer is supposed to be a fresh start, so we do it for user timers. For the direct snd_timer_continue() call, there is no way to pass the initial tick value, so we kick out for the uninitialized case. Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> [bwh: Backported to 3.16: - Adjust context - In _snd_timer_stop(), check the value of 'event' instead of 'stop'] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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