syzbot


WARNING in memdup_user_nul

Status: fixed on 2021/04/09 19:46
Reported-by: syzbot+a71a442385a0b2815497@syzkaller.appspotmail.com
Fix commit: 7ef4c19d245f smackfs: restrict bytes count in smackfs write functions
First crash: 629d, last: 629d

Cause bisection: the issue happens on the oldest tested release (bisect log)
Crash: WARNING in sysfs_warn_dup (log)
Repro: C syz .config
duplicates (5):
Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
WARNING in smk_write_net4addr C inconclusive 10 595d 628d 0/24 closed as dup on 2021/01/20 02:55
WARNING in smk_set_cipso C inconclusive 19 544d 625d 0/24 closed as dup on 2021/01/20 02:53
WARNING in smk_write_net6addr C inconclusive 20 596d 624d 0/24 closed as dup on 2021/01/20 02:52
WARNING in smk_write_relabel_self C inconclusive 20 596d 629d 0/24 closed as dup on 2021/01/20 02:55
WARNING in smk_write_syslog C inconclusive 13 590d 623d 0/24 closed as dup on 2021/01/20 02:52
Patch testing requests:
Created Duration User Patch Repo Result
2021/01/28 11:39 17m snovitoll@gmail.com https://linux.googlesource.com/linux/kernel/git/torvalds/linux refs/changes/96/7796/1 OK
2021/01/24 13:36 17m snovitoll@gmail.com https://linux.googlesource.com/linux/kernel/git/torvalds/linux refs/changes/16/7716/4 OK
2021/01/24 13:24 2m snovitoll@gmail.com git://linux.googlesource.com/linux/kernel/git/torvalds/linux.git 61280bbe04b114ac4d422304b67a79c6671dc8ee error
2021/01/24 11:55 2m snovitoll@gmail.com git://linux.googlesource.com/linux/kernel/git/torvalds/linux.git refs/changes/16/7716/4 error

Sample crash report:
------------[ cut here ]------------
WARNING: CPU: 0 PID: 8449 at mm/page_alloc.c:4976 __alloc_pages_nodemask+0x4e5/0x5a0 mm/page_alloc.c:5020
Modules linked in:
CPU: 0 PID: 8449 Comm: syz-executor564 Not tainted 5.11.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__alloc_pages_nodemask+0x4e5/0x5a0 mm/page_alloc.c:5020
Code: aa 09 00 e9 dd fd ff ff 44 89 e9 80 e1 07 80 c1 03 38 c1 0f 8c eb fd ff ff 4c 89 ef e8 54 aa 09 00 8b 74 24 18 e9 da fd ff ff <0f> 0b e9 f3 fd ff ff a9 00 00 08 00 75 16 8b 4c 24 1c 89 cb 81 e3
RSP: 0018:ffffc90000ebfa60 EFLAGS: 00010246
RAX: ffffc90000ebfae0 RBX: ffffc90000ebfae0 RCX: 0000000000000000
RDX: 0000000000000028 RSI: 0000000000000000 RDI: ffffc90000ebfb08
RBP: ffffc90000ebfba0 R08: dffffc0000000000 R09: ffffc90000ebfae0
R10: fffff520001d7f61 R11: 0000000000000000 R12: dffffc0000000000
R13: 0000000000000012 R14: 1ffff920001d7f58 R15: 0000000000040cc0
FS:  0000000002595880(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000040 CR3: 0000000015a93000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 alloc_pages include/linux/gfp.h:547 [inline]
 kmalloc_order+0x40/0x130 mm/slab_common.c:837
 kmalloc_order_trace+0x15/0x70 mm/slab_common.c:853
 kmalloc_large include/linux/slab.h:481 [inline]
 __kmalloc_track_caller+0x246/0x330 mm/slub.c:4457
 memdup_user_nul+0x26/0xf0 mm/util.c:260
 smk_write_syslog+0x29/0x90 security/smack/smackfs.c:2651
 vfs_write+0x289/0xc90 fs/read_write.c:603
 ksys_write+0x171/0x2a0 fs/read_write.c:658
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x440289
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 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 7b 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fffe1057358 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440289
RDX: 00000000200000cb RSI: 00000000200000c0 RDI: 0000000000000003
RBP: 00000000006ca018 R08: 0000000000000000 R09: 00000000004002c8
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401a90
R13: 0000000000401b20 R14: 0000000000000000 R15: 0000000000000000

Crashes (2):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce-smack-root 2021/01/14 10:02 upstream 65f0d2414b70 269d24e8 .config log report syz C
ci-upstream-kasan-gce-smack-root 2021/01/14 09:50 upstream 65f0d2414b70 269d24e8 .config log report info
* Struck through repros no longer work on HEAD.