On Wed, Jan 2, 2019 at 12:36 PM syzbot <syzbot+d6ed4ec679652b4fd4e4@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > Hello, > > syzbot found the following crash on: > > HEAD commit: 903b77c63167 Merge tag 'linux-kselftest-4.21-rc1' of git:/.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=133428e3400000 > kernel config: https://syzkaller.appspot.com/x/.config?x=53a2f2aa0b1f7606 > dashboard link: https://syzkaller.appspot.com/bug?extid=d6ed4ec679652b4fd4e4 > compiler: gcc (GCC) 8.0.1 20180413 (experimental) > > Unfortunately, I don't have any reproducer for this crash yet. > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+d6ed4ec679652b4fd4e4@xxxxxxxxxxxxxxxxxxxxxxxxx +mm maintianers Am I missing something or __alloc_alien_cache misses check for kmalloc_node result? static struct alien_cache *__alloc_alien_cache(int node, int entries, int batch, gfp_t gfp) { size_t memsize = sizeof(void *) * entries + sizeof(struct alien_cache); struct alien_cache *alc = NULL; alc = kmalloc_node(memsize, gfp, node); init_arraycache(&alc->ac, entries, batch); spin_lock_init(&alc->lock); return alc; } > BUG: unable to handle kernel NULL pointer dereference at 0000000000000038 > #PF error: [WRITE] > PGD 8b2a5067 P4D 8b2a5067 PUD a53ed067 PMD 0 > Oops: 0002 [#1] PREEMPT SMP KASAN > CPU: 1 PID: 16188 Comm: syz-executor4 Not tainted 4.20.0+ #174 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > RIP: 0010:init_arraycache mm/slab.c:562 [inline] > RIP: 0010:__alloc_alien_cache mm/slab.c:669 [inline] > RIP: 0010:alloc_alien_cache mm/slab.c:689 [inline] > RIP: 0010:setup_kmem_cache_node+0x1ed/0x400 mm/slab.c:910 > Code: 63 48 63 c3 48 0f a3 05 59 9c 72 08 73 56 8b 75 b8 4d 8d 2c c6 44 89 > e2 48 8b 7d a8 e8 fc e9 ff ff 48 83 f8 c8 49 89 c7 74 17 <c7> 40 38 00 00 > 00 00 8b 45 b0 41 89 47 3c b8 0d f0 ad ba 49 89 47 > RSP: 0018:ffff88804e827318 EFLAGS: 00010213 > RAX: 0000000000000000 RBX: 0000000000000001 RCX: 00000000006000c0 > RDX: 00000000000000a8 RSI: 0000000000000000 RDI: ffff88812c3f0040 > RBP: ffff88804e827378 R08: ffff888054cc86c0 R09: ffffed1015ce5b8f > R10: ffffed1015ce5b8f R11: ffff8880ae72dc7b R12: 0000000000000000 > R13: ffff888095642648 R14: ffff888095642640 R15: 0000000000000000 > FS: 00007f6fef838700(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000000000000038 CR3: 000000005034d000 CR4: 00000000001406e0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > setup_kmem_cache_nodes mm/slab.c:3819 [inline] > __do_tune_cpucache+0x165/0x220 mm/slab.c:3889 > do_tune_cpucache+0x25/0xd0 mm/slab.c:3898 > enable_cpucache+0x3e/0xd0 mm/slab.c:3979 > setup_cpu_cache+0xd4/0x1e0 mm/slab.c:1821 > __kmem_cache_create+0x191/0x230 mm/slab.c:2134 > create_cache+0xcd/0x1f0 mm/slab_common.c:391 > kmem_cache_create_usercopy+0x18a/0x240 mm/slab_common.c:487 > p9_client_create+0x986/0x1674 net/9p/client.c:1054 > v9fs_session_init+0x217/0x1bb0 fs/9p/v9fs.c:421 > v9fs_mount+0x7c/0x8f0 fs/9p/vfs_super.c:135 > mount_fs+0xae/0x31d fs/super.c:1261 > kobject: 'loop1' (000000003afcedd0): kobject_uevent_env > vfs_kern_mount.part.35+0xdc/0x4f0 fs/namespace.c:961 > kobject: 'loop1' (000000003afcedd0): fill_kobj_path: path > = '/devices/virtual/block/loop1' > vfs_kern_mount fs/namespace.c:951 [inline] > do_new_mount fs/namespace.c:2469 [inline] > do_mount+0x581/0x31f0 fs/namespace.c:2801 > kobject: 'loop2' (00000000108c69f3): kobject_uevent_env > kobject: 'loop2' (00000000108c69f3): fill_kobj_path: path > = '/devices/virtual/block/loop2' > ksys_mount+0x12d/0x140 fs/namespace.c:3017 > __do_sys_mount fs/namespace.c:3031 [inline] > __se_sys_mount fs/namespace.c:3028 [inline] > __x64_sys_mount+0xbe/0x150 fs/namespace.c:3028 > do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > RIP: 0033:0x4579b9 > Code: fd b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 > 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff > ff 0f 83 cb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 > RSP: 002b:00007f6fef837c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 > RAX: ffffffffffffffda RBX: 00007f6fef837c90 RCX: 00000000004579b9 > RDX: 0000000020000000 RSI: 00000000200000c0 RDI: 0000000000000000 > RBP: 000000000073bf00 R08: 0000000020000240 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000246 R12: 00007f6fef8386d4 > R13: 00000000004c369b R14: 00000000004d61f8 R15: 0000000000000005 > Modules linked in: > CR2: 0000000000000038 > ---[ end trace c630b12329ae5f74 ]--- > RIP: 0010:init_arraycache mm/slab.c:562 [inline] > RIP: 0010:__alloc_alien_cache mm/slab.c:669 [inline] > RIP: 0010:alloc_alien_cache mm/slab.c:689 [inline] > RIP: 0010:setup_kmem_cache_node+0x1ed/0x400 mm/slab.c:910 > kobject: 'loop3' (00000000e06f18ba): kobject_uevent_env > Code: 63 48 63 c3 48 0f a3 05 59 9c 72 08 73 56 8b 75 b8 4d 8d 2c c6 44 89 > e2 48 8b 7d a8 e8 fc e9 ff ff 48 83 f8 c8 49 89 c7 74 17 <c7> 40 38 00 00 > 00 00 8b 45 b0 41 89 47 3c b8 0d f0 ad ba 49 89 47 > kobject: 'loop3' (00000000e06f18ba): fill_kobj_path: path > = '/devices/virtual/block/loop3' > RSP: 0018:ffff88804e827318 EFLAGS: 00010213 > kobject: 'loop5' (00000000bc6ae381): kobject_uevent_env > RAX: 0000000000000000 RBX: 0000000000000001 RCX: 00000000006000c0 > kobject: 'loop5' (00000000bc6ae381): fill_kobj_path: path > = '/devices/virtual/block/loop5' > RDX: 00000000000000a8 RSI: 0000000000000000 RDI: ffff88812c3f0040 > kobject: 'loop3' (00000000e06f18ba): kobject_uevent_env > kobject: 'loop3' (00000000e06f18ba): fill_kobj_path: path > = '/devices/virtual/block/loop3' > RBP: ffff88804e827378 R08: ffff888054cc86c0 R09: ffffed1015ce5b8f > kobject: 'loop1' (000000003afcedd0): kobject_uevent_env > R10: ffffed1015ce5b8f R11: ffff8880ae72dc7b R12: 0000000000000000 > kobject: 'loop1' (000000003afcedd0): fill_kobj_path: path > = '/devices/virtual/block/loop1' > R13: ffff888095642648 R14: ffff888095642640 R15: 0000000000000000 > FS: 00007f6fef838700(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000000000400200 CR3: 000000005034d000 CR4: 00000000001406f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > > > --- > This bug is generated by a bot. It may contain errors. > See https://goo.gl/tpsmEJ for more information about syzbot. > syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. > > syzbot will keep track of this bug report. See: > https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with > syzbot. > > -- > You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group. > To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-bugs+unsubscribe@xxxxxxxxxxxxxxxx. > To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/0000000000000f35c6057e780d36%40google.com. > For more options, visit https://groups.google.com/d/optout.
