On Tue, 2017-01-31 at 14:16 +0100, Dmitry Vyukov wrote: > Hello, > > I am getting the following reports with low frequency while running > syzkaller fuzzer. Unfortunately they are not reproducible and happen > in a background thread, so it is difficult to extract any context on > my side. I see only few such crashes per week, so most likely it is > some hard to trigger data race. The following reports are from mmotm > tree, commits 00e20cfc2bf04a0cbe1f5405f61c8426f43eee84 and > fff7e71eac7788904753136f09bcad7471f7799e. Any ideas as to how this can > happen? Wonder if there is a race between the flusher thread that flush out existing jobs if we don't have incoming jobs for a while and computation via mcryptd. Maybe the flusher fires at the same time when there is a new job arriving. Let Megha and I think a bit about it to come up with a patch to see if that's the case. Tim > > BUG: unable to handle kernel NULL pointer dereference at 0000000000000060 > IP: [<ffffffff813fc09e>] sha512_mb_mgr_get_comp_job_avx2+0x6e/0xee > arch/x86/crypto/sha512-mb/sha512_mb_mgr_flush_avx2.S:251 > PGD 1d2395067 [ 220.874864] PUD 1d2860067 > Oops: 0002 [#1] SMP KASAN > Dumping ftrace buffer: > (ftrace buffer empty) > Modules linked in: > CPU: 0 PID: 516 Comm: kworker/0:1 Not tainted 4.9.0 #4 > Hardware name: Google Google Compute Engine/Google Compute Engine, > BIOS Google 01/01/2011 > Workqueue: crypto mcryptd_queue_worker > task: ffff8801d9f346c0 task.stack: ffff8801d9f08000 > RIP: 0010:[<ffffffff813fc09e>] [<ffffffff813fc09e>] > sha512_mb_mgr_get_comp_job_avx2+0x6e/0xee > arch/x86/crypto/sha512-mb/sha512_mb_mgr_flush_avx2.S:251 > RSP: 0018:ffff8801d9f0eef8 EFLAGS: 00010202 > RAX: 0000000000000000 RBX: ffff8801d7db1190 RCX: 0000000000000006 > RDX: 0000000000000001 RSI: ffff8801d9f34ee8 RDI: ffff8801d7db1040 > RBP: ffff8801d9f0f258 R08: 0000000100000000 R09: 0000000000000001 > R10: 0000000000000002 R11: 0000000000000003 R12: ffff8801d9f0f230 > R13: ffff8801c8bbc4e0 R14: ffff8801c8bbc530 R15: ffff8801d9f0ef70 > FS: 0000000000000000(0000) GS:ffff8801dc000000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000000000000060 CR3: 00000001cc15a000 CR4: 00000000001406f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Stack: > ffff8801d7db1040 ffffffff813fa207 dffffc0000000000 ffffe8ffffc0f238 > 0000000000000002 1ffff1003b3e1dea ffffe8ffffc0f218 ffff8801d9f0f190 > 0000000000000282 ffffe8ffffc0f140 ffffe8ffffc0f220 0000000041b58ab3 > Call Trace: > [<ffffffff813fb407>] sha512_mb_update+0x2f7/0x4e0 > arch/x86/crypto/sha512-mb/sha512_mb.c:588 > [<ffffffff8219d4ad>] crypto_ahash_update include/crypto/hash.h:512 [inline] > [<ffffffff8219d4ad>] ahash_mcryptd_update crypto/mcryptd.c:627 [inline] > [<ffffffff8219d4ad>] mcryptd_hash_update+0xcd/0x1c0 crypto/mcryptd.c:373 > [<ffffffff8219c99f>] mcryptd_queue_worker+0xff/0x6a0 crypto/mcryptd.c:181 > [<ffffffff81492960>] process_one_work+0xbd0/0x1c10 kernel/workqueue.c:2096 > [<ffffffff81493bc3>] worker_thread+0x223/0x1990 kernel/workqueue.c:2230 > [<ffffffff814abb33>] kthread+0x323/0x3e0 kernel/kthread.c:209 > [<ffffffff8436fbaa>] ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:433 > Code: 49 0f 42 d3 48 f7 c2 f0 ff ff ff 0f 85 9a 00 00 00 48 83 e2 0f > 48 6b da 08 48 8d 9c 1f 48 01 00 00 48 8b 03 48 c7 03 00 00 00 00 <c7> > 40 60 02 00 00 00 48 8b 9f 40 01 00 00 48 c1 e3 08 48 09 d3 > RIP [<ffffffff813fc09e>] sha512_mb_mgr_get_comp_job_avx2+0x6e/0xee > arch/x86/crypto/sha512-mb/sha512_mb_mgr_flush_avx2.S:251 > RSP <ffff8801d9f0eef8> > CR2: 0000000000000060 > ---[ end trace 139fd4cda5dfe2c4 ]--- > > BUG: unable to handle kernel NULL pointer dereference at 0000000000000060 > IP: [<ffffffff813fc09e>] sha512_mb_mgr_get_comp_job_avx2+0x6e/0xee > arch/x86/crypto/sha512-mb/sha512_mb_mgr_flush_avx2.S:251 > PGD 1c68ad067 [ 624.973638] PUD 1d485a067 > Oops: 0002 [#1] SMP KASAN > Dumping ftrace buffer: > (ftrace buffer empty) > Modules linked in: > CPU: 0 PID: 517 Comm: kworker/0:1 Not tainted 4.9.0 #3 > Hardware name: Google Google Compute Engine/Google Compute Engine, > BIOS Google 01/01/2011 > Workqueue: crypto mcryptd_queue_worker > task: ffff8801d9e64700 task.stack: ffff8801d9838000 > RIP: 0010:[<ffffffff813fc09e>] [<ffffffff813fc09e>] > sha512_mb_mgr_get_comp_job_avx2+0x6e/0xee > arch/x86/crypto/sha512-mb/sha512_mb_mgr_flush_avx2.S:251 > RSP: 0018:ffff8801d983eef8 EFLAGS: 00010202 > RAX: 0000000000000000 RBX: ffff8801d7d96950 RCX: 0000000000000006 > RDX: 0000000000000001 RSI: ffff8801d9e64f28 RDI: ffff8801d7d96800 > RBP: ffff8801d983f258 R08: 0000000100000000 R09: 0000000000000001 > R10: 0000000000000002 R11: 0000000000000003 R12: ffff8801d983f230 > R13: ffff8801b67f5720 R14: ffff8801b67f5770 R15: ffff8801d983ef70 > FS: 0000000000000000(0000) GS:ffff8801dc000000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000000000000060 CR3: 00000001cee58000 CR4: 00000000001406f0 > Stack: > ffff8801d7d96800 ffffffff813fa207 dffffc0000000000 ffffe8ffffc0f238 > 0000000000000002 1ffff1003b307dea ffffe8ffffc0f218 ffff8801d983f190 > 0000000000000282 ffffe8ffffc0f140 ffffe8ffffc0f220 0000000041b58ab3 > Call Trace: > [<ffffffff813fb407>] sha512_mb_update+0x2f7/0x4e0 > arch/x86/crypto/sha512-mb/sha512_mb.c:588 > [<ffffffff8219cdad>] crypto_ahash_update include/crypto/hash.h:512 [inline] > [<ffffffff8219cdad>] ahash_mcryptd_update crypto/mcryptd.c:627 [inline] > [<ffffffff8219cdad>] mcryptd_hash_update+0xcd/0x1c0 crypto/mcryptd.c:373 > [<ffffffff8219c29f>] mcryptd_queue_worker+0xff/0x6a0 crypto/mcryptd.c:181 > [<ffffffff81492960>] process_one_work+0xbd0/0x1c10 kernel/workqueue.c:2096 > [<ffffffff81493bc3>] worker_thread+0x223/0x1990 kernel/workqueue.c:2230 > [<ffffffff814abb33>] kthread+0x323/0x3e0 kernel/kthread.c:209 > [<ffffffff8436fbea>] ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:433 > Code: 49 0f 42 d3 48 f7 c2 f0 ff ff ff 0f 85 9a 00 00 00 48 83 e2 0f > 48 6b da 08 48 8d 9c 1f 48 01 00 00 48 8b 03 48 c7 03 00 00 00 00 <c7> > 40 60 02 00 00 00 48 8b 9f 40 01 00 00 48 c1 e3 08 48 09 d3 > RIP [<ffffffff813fc09e>] sha512_mb_mgr_get_comp_job_avx2+0x6e/0xee > arch/x86/crypto/sha512-mb/sha512_mb_mgr_flush_avx2.S:251 > RSP <ffff8801d983eef8> > CR2: 0000000000000060 > ---[ end trace 76403e033556dcb7 ]--- > > BUG: unable to handle kernel NULL pointer dereference at 0000000000000060 > IP: [<ffffffff813fc09e>] sha512_mb_mgr_get_comp_job_avx2+0x6e/0xee > arch/x86/crypto/sha512-mb/sha512_mb_mgr_flush_avx2.S:251 > PGD 1d6242067 [ 226.248182] PUD 1d2093067 > Oops: 0002 [#1] SMP KASAN > Dumping ftrace buffer: > (ftrace buffer empty) > Modules linked in: > CPU: 1 PID: 1788 Comm: kworker/1:2 Not tainted 4.9.0 #3 > Hardware name: Google Google Compute Engine/Google Compute Engine, > BIOS Google 01/01/2011 > Workqueue: crypto mcryptd_queue_worker > task: ffff8801cc3ee100 task.stack: ffff8801cd068000 > RIP: 0010:[<ffffffff813fc09e>] [<ffffffff813fc09e>] > sha512_mb_mgr_get_comp_job_avx2+0x6e/0xee > arch/x86/crypto/sha512-mb/sha512_mb_mgr_flush_avx2.S:251 > RSP: 0018:ffff8801cd06eef8 EFLAGS: 00010202 > RAX: 0000000000000000 RBX: ffff8801d7dc3c10 RCX: 0000000000000006 > RDX: 0000000000000001 RSI: ffff8801cc3ee928 RDI: ffff8801d7dc3ac0 > RBP: ffff8801cd06f258 R08: 0000000100000000 R09: 0000000000000001 > R10: 0000000000000002 R11: 0000000000000003 R12: ffff8801cd06f230 > R13: ffff8801c6eb9aa0 R14: ffff8801c6eb9af0 R15: ffff8801cd06ef70 > FS: 0000000000000000(0000) GS:ffff8801dc100000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000000000000060 CR3: 00000001d6201000 CR4: 00000000001406e0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Stack: > ffff8801d7dc3ac0 ffffffff813fa207 dffffc0000000000 ffffe8ffffd0f238 > 0000000000000002 1ffff10039a0ddea ffffe8ffffd0f218 ffff8801cd06f190 > 0000000000000282 ffffe8ffffd0f140 ffffe8ffffd0f220 0000000041b58ab3 > Call Trace: > [<ffffffff813fb407>] sha512_mb_update+0x2f7/0x4e0 > arch/x86/crypto/sha512-mb/sha512_mb.c:588 > [<ffffffff8219cdad>] crypto_ahash_update include/crypto/hash.h:512 [inline] > [<ffffffff8219cdad>] ahash_mcryptd_update crypto/mcryptd.c:627 [inline] > [<ffffffff8219cdad>] mcryptd_hash_update+0xcd/0x1c0 crypto/mcryptd.c:373 > [<ffffffff8219c29f>] mcryptd_queue_worker+0xff/0x6a0 crypto/mcryptd.c:181 > [<ffffffff81492960>] process_one_work+0xbd0/0x1c10 kernel/workqueue.c:2096 > [<ffffffff81493bc3>] worker_thread+0x223/0x1990 kernel/workqueue.c:2230 > [<ffffffff814abb33>] kthread+0x323/0x3e0 kernel/kthread.c:209 > [<ffffffff8436fbea>] ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:433 > Code: 49 0f 42 d3 48 f7 c2 f0 ff ff ff 0f 85 9a 00 00 00 48 83 e2 0f > 48 6b da 08 48 8d 9c 1f 48 01 00 00 48 8b 03 48 c7 03 00 00 00 00 <c7> > 40 60 02 00 00 00 48 8b 9f 40 01 00 00 48 c1 e3 08 48 09 d3 > RIP [<ffffffff813fc09e>] sha512_mb_mgr_get_comp_job_avx2+0x6e/0xee > arch/x86/crypto/sha512-mb/sha512_mb_mgr_flush_avx2.S:251 > RSP <ffff8801cd06eef8> > CR2: 0000000000000060 > ---[ end trace 47d3302a6c62cfbc ]--- > > BUG: unable to handle kernel NULL pointer dereference at 0000000000000060 > IP: [<ffffffff813fc09e>] sha512_mb_mgr_get_comp_job_avx2+0x6e/0xee > arch/x86/crypto/sha512-mb/sha512_mb_mgr_flush_avx2.S:251 > PGD 1ccad4067 [ 32.785777] PUD 1cb96c067 > Oops: 0002 [#1] SMP KASAN > Dumping ftrace buffer: > (ftrace buffer empty) > Modules linked in: > CPU: 1 PID: 3231 Comm: kworker/1:2 Not tainted 4.9.0 #3 > Hardware name: Google Google Compute Engine/Google Compute Engine, > BIOS Google 01/01/2011 > Workqueue: crypto mcryptd_queue_worker > task: ffff8801cf472700 task.stack: ffff8801ce848000 > RIP: 0010:[<ffffffff813fc09e>] [<ffffffff813fc09e>] > sha512_mb_mgr_get_comp_job_avx2+0x6e/0xee > arch/x86/crypto/sha512-mb/sha512_mb_mgr_flush_avx2.S:251 > RSP: 0018:ffff8801ce84eef8 EFLAGS: 00010202 > RAX: 0000000000000000 RBX: ffff8801d7c82950 RCX: 0000000000000006 > RDX: 0000000000000001 RSI: ffff8801cf472f28 RDI: ffff8801d7c82800 > RBP: ffff8801ce84f258 R08: 0000000100000000 R09: 0000000000000001 > R10: 0000000000000002 R11: 0000000000000003 R12: ffff8801ce84f230 > R13: ffff8801c970e760 R14: ffff8801c970e7b0 R15: ffff8801ce84ef70 > FS: 0000000000000000(0000) GS:ffff8801dc100000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000000000000060 CR3: 00000001ca654000 CR4: 00000000001406e0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Stack: > ffff8801d7c82800 ffffffff813fa207 dffffc0000000000 ffffe8ffffd0f238 > 0000000000000002 1ffff10039d09dea ffffe8ffffd0f218 ffff8801ce84f190 > 0000000000000282 ffffe8ffffd0f140 ffffe8ffffd0f220 0000000041b58ab3 > Call Trace: > [<ffffffff813fb407>] sha512_mb_update+0x2f7/0x4e0 > arch/x86/crypto/sha512-mb/sha512_mb.c:588 > [<ffffffff8219cdad>] crypto_ahash_update include/crypto/hash.h:512 [inline] > [<ffffffff8219cdad>] ahash_mcryptd_update crypto/mcryptd.c:627 [inline] > [<ffffffff8219cdad>] mcryptd_hash_update+0xcd/0x1c0 crypto/mcryptd.c:373 > [<ffffffff8219c29f>] mcryptd_queue_worker+0xff/0x6a0 crypto/mcryptd.c:181 > [<ffffffff81492960>] process_one_work+0xbd0/0x1c10 kernel/workqueue.c:2096 > [<ffffffff81493bc3>] worker_thread+0x223/0x1990 kernel/workqueue.c:2230 > [<ffffffff814abb33>] kthread+0x323/0x3e0 kernel/kthread.c:209 > [<ffffffff8436fbea>] ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:433 > Code: 49 0f 42 d3 48 f7 c2 f0 ff ff ff 0f 85 9a 00 00 00 48 83 e2 0f > 48 6b da 08 48 8d 9c 1f 48 01 00 00 48 8b 03 48 c7 03 00 00 00 00 <c7> > 40 60 02 00 00 00 48 8b 9f 40 01 00 00 48 c1 e3 08 48 09 d3 > RIP [<ffffffff813fc09e>] sha512_mb_mgr_get_comp_job_avx2+0x6e/0xee > arch/x86/crypto/sha512-mb/sha512_mb_mgr_flush_avx2.S:251 > RSP <ffff8801ce84eef8> > CR2: 0000000000000060 > ---[ end trace 3af8184eabd21203 ]--- -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
