WARNING in memdup_user_nul

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 65f0d241 Merge tag 'sound-5.11-rc4' of git://git.kernel.or..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=11753ee0d00000
kernel config: https://syzkaller.appspot.com/x/.config?x=ee2266946ed36986
dashboard link: https://syzkaller.appspot.com/bug?extid=a71a442385a0b2815497
compiler: clang version 11.0.0 (https://github.com/llvm/llvm-project.git ca2dcbd030eadbf0aa9b660efe864ff08af6e18b)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=152fba3f500000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=176728e7500000

Bisection is inconclusive: the issue happens on the oldest tested release.

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=12cf2548d00000
final oops: https://syzkaller.appspot.com/x/report.txt?x=11cf2548d00000
console output: https://syzkaller.appspot.com/x/log.txt?x=16cf2548d00000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+a71a44...@syzkaller.appspotmail.com

------------[ 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


---
This report 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 syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
For information about bisection process see: https://goo.gl/tpsmEJ#bisection
syzbot can test patches for this issue, for details see:
https://goo.gl/tpsmEJ#testing-patches

[syzbot]

Hello,

syzbot tried to test the proposed patch but the build/boot failed:

failed to checkout kernel repo git://linux.googlesource.com/linux/kernel/git/torvalds/linux.git/refs/changes/16/7716/4: failed to run ["git" "fetch" "--force" "84c7ffe80d8065a6437846ae839cd9b246d756c1" "refs/changes/16/7716/4"]: exit status 128
fatal: unable to connect to linux.googlesource.com:
linux.googlesource.com[0: 172.217.212.82]: errno=Connection timed out
linux.googlesource.com[1: 2607:f8b0:4001:c03::52]: errno=Network is unreachable




Tested on:

commit: [unknown
git tree: git://linux.googlesource.com/linux/kernel/git/torvalds/linux.git refs/changes/16/7716/4
dashboard link: https://syzkaller.appspot.com/bug?extid=a71a442385a0b2815497
compiler: clang version 11.0.1

[syzbot]

Hello,

syzbot tried to test the proposed patch but the build/boot failed:

failed to checkout kernel repo git://linux.googlesource.com/linux/kernel/git/torvalds/linux.git on commit 61280bbe04b114ac4d422304b67a79c6671dc8ee: failed to run ["git" "fetch" "--force" "--tags" "84c7ffe80d8065a6437846ae839cd9b246d756c1"]: exit status 128

fatal: unable to connect to linux.googlesource.com:
linux.googlesource.com[0: 172.217.212.82]: errno=Connection timed out
linux.googlesource.com[1: 2607:f8b0:4001:c03::52]: errno=Network is unreachable




Tested on:

commit: [unknown

git tree: git://linux.googlesource.com/linux/kernel/git/torvalds/linux.git 61280bbe04b114ac4d422304b67a79c6671dc8ee

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-and-tested-by: syzbot+a71a44...@syzkaller.appspotmail.com

Tested on:

commit: 61280bbe smackfs: restrict bytes count before memdup_user_..
git tree: https://linux.googlesource.com/linux/kernel/git/torvalds/linux refs/changes/16/7716/4
kernel config: https://syzkaller.appspot.com/x/.config?x=c5f3af3f625fb042

dashboard link: https://syzkaller.appspot.com/bug?extid=a71a442385a0b2815497
compiler: clang version 11.0.1

Note: testing is done by a robot and is best-effort only.

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-and-tested-by: syzbot+a71a44...@syzkaller.appspotmail.com

Tested on:

commit: 262e68bf smackfs: restrict bytes count before memdup_user_..
git tree: https://linux.googlesource.com/linux/kernel/git/torvalds/linux refs/changes/96/7796/1
kernel config: https://syzkaller.appspot.com/x/.config?x=e86c8ff11b79cd1a