Re: [syzbot] [cgroups?] [mm?] kernel BUG in swap_cgroup_record

[Barry Song]

On Fri, Aug 16, 2024 at 1:28 PM syzbot
<syzbot+4745e725b07d34503a64@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
>
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit:    9e6869691724 Add linux-next specific files for 20240812
> git tree:       linux-next
> console output: https://syzkaller.appspot.com/x/log.txt?x=14c97e83980000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=61ba6f3b22ee5467
> dashboard link: https://syzkaller.appspot.com/bug?extid=4745e725b07d34503a64
> compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=10cf435d980000
>
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/f1b086192f50/disk-9e686969.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/b457920fb52e/vmlinux-9e686969.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/e63ba9cce98a/bzImage-9e686969.xz
>
> The issue was bisected to:
>
> commit d65aea610f0a14cda5ec56a154c724584ef7da17
> Author: Barry Song <v-songbaohua@xxxxxxxx>
> Date:   Wed Aug 7 21:58:59 2024 +0000
>
>     mm: attempt to batch free swap entries for zap_pte_range()
>
> bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=1493ea91980000
> final oops:     https://syzkaller.appspot.com/x/report.txt?x=1693ea91980000
> console output: https://syzkaller.appspot.com/x/log.txt?x=1293ea91980000
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+4745e725b07d34503a64@xxxxxxxxxxxxxxxxxxxxxxxxx
> Fixes: d65aea610f0a ("mm: attempt to batch free swap entries for zap_pte_range()")
>
> ------------[ cut here ]------------
> kernel BUG at mm/swap_cgroup.c:141!

thanks! this is exactly what Chris and Yosry have reported:

https://lore.kernel.org/all/20240815215308.55233-1-21cnbao@xxxxxxxxx/

And this one is queued:
+ mm-attempt-to-batch-free-swap-entries-for-zap_pte_range-fix.patch
added to mm-unstable branch
https://lore.kernel.org/all/20240815221312.94782C32786@xxxxxxxxxxxxxxx/


> Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
> CPU: 1 UID: 0 PID: 5371 Comm: syz.0.15 Not tainted 6.11.0-rc3-next-20240812-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
> RIP: 0010:swap_cgroup_record+0x2cd/0x2d0 mm/swap_cgroup.c:141
> Code: e7 e8 a7 c9 f6 ff e9 64 fe ff ff e8 cd 41 8e ff 48 c7 c7 c0 db a5 8e 48 89 de e8 2e 8c e8 02 e9 7a fd ff ff e8 b4 41 8e ff 90 <0f> 0b 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 0f 1f
> RSP: 0018:ffffc90003e172f8 EFLAGS: 00010093
> RAX: ffffffff82054c9c RBX: 000000000000000b RCX: ffff88802298bc00
> RDX: 0000000000000000 RSI: 000000000000000a RDI: 0000000000000000
> RBP: 0000000000000001 R08: ffffffff82054b43 R09: fffff520007c2e3c
> R10: dffffc0000000000 R11: fffff520007c2e3c R12: ffff88801cf0f014
> R13: 0000000000000000 R14: 000000000000000a R15: 0000000000000000
> FS:  0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007f9332107a8c CR3: 000000000e734000 CR4: 00000000003506f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
>  <TASK>
>  __mem_cgroup_uncharge_swap+0x84/0x2e0 mm/memcontrol.c:5118
>  mem_cgroup_uncharge_swap include/linux/swap.h:668 [inline]
>  swap_entry_range_free+0x45f/0x1120 mm/swapfile.c:1556
>  __swap_entries_free mm/swapfile.c:1518 [inline]
>  free_swap_and_cache_nr+0xa65/0xae0 mm/swapfile.c:1876
>  zap_pte_range mm/memory.c:1653 [inline]
>  zap_pmd_range mm/memory.c:1736 [inline]
>  zap_pud_range mm/memory.c:1765 [inline]
>  zap_p4d_range mm/memory.c:1786 [inline]
>  unmap_page_range+0x1924/0x42c0 mm/memory.c:1807
>  unmap_vmas+0x3cc/0x5f0 mm/memory.c:1897
>  exit_mmap+0x267/0xc20 mm/mmap.c:1923
>  __mmput+0x115/0x390 kernel/fork.c:1347
>  exit_mm+0x220/0x310 kernel/exit.c:571
>  do_exit+0x9b2/0x28e0 kernel/exit.c:926
>  do_group_exit+0x207/0x2c0 kernel/exit.c:1088
>  __do_sys_exit_group kernel/exit.c:1099 [inline]
>  __se_sys_exit_group kernel/exit.c:1097 [inline]
>  __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1097
>  x64_sys_call+0x2634/0x2640 arch/x86/include/generated/asm/syscalls_64.h:232
>  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
>  do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
>  entry_SYSCALL_64_after_hwframe+0x77/0x7f
> RIP: 0033:0x7f9331f779f9
> Code: Unable to access opcode bytes at 0x7f9331f779cf.
> RSP: 002b:00007fff65ce5d18 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
> RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f9331f779f9
> RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
> RBP: 0000000000000003 R08: 00007fff65ce5dff R09: 00007f93320d0260
> R10: 0000000000000001 R11: 0000000000000246 R12: 00007f93320d0f68
> R13: 00007f93320d0260 R14: 0000000000000003 R15: 00007fff65ce5dc0
>  </TASK>
> Modules linked in:
> ---[ end trace 0000000000000000 ]---
> RIP: 0010:swap_cgroup_record+0x2cd/0x2d0 mm/swap_cgroup.c:141
> Code: e7 e8 a7 c9 f6 ff e9 64 fe ff ff e8 cd 41 8e ff 48 c7 c7 c0 db a5 8e 48 89 de e8 2e 8c e8 02 e9 7a fd ff ff e8 b4 41 8e ff 90 <0f> 0b 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 0f 1f
> RSP: 0018:ffffc90003e172f8 EFLAGS: 00010093
> RAX: ffffffff82054c9c RBX: 000000000000000b RCX: ffff88802298bc00
> RDX: 0000000000000000 RSI: 000000000000000a RDI: 0000000000000000
> RBP: 0000000000000001 R08: ffffffff82054b43 R09: fffff520007c2e3c
> R10: dffffc0000000000 R11: fffff520007c2e3c R12: ffff88801cf0f014
> R13: 0000000000000000 R14: 000000000000000a R15: 0000000000000000
> FS:  0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007f9332107a8c CR3: 000000000e734000 CR4: 00000000003506f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
>
>
> ---
> This report is generated by a bot. It may contain errors.
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>
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Thanks
Barry