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+a71a442385a0b2815497 at syzkaller.appspotmail.com

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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


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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