lkml.org 
[lkml]   [2022]   [Aug]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [syzbot] BUG: unable to handle kernel NULL pointer dereference in set_page_dirty
On 08/25, Andrew Morton wrote:
> (cc fsf2 developers)
>
> On Thu, 25 Aug 2022 08:29:32 -0700 syzbot <syzbot+775a3440817f74fddb8c@syzkaller.appspotmail.com> wrote:
>
> > Hello,
> >
> > syzbot found the following issue on:
> >
> > HEAD commit: a41a877bc12d Merge branch 'for-next/fixes' into for-kernelci
> > git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
> > console output: https://syzkaller.appspot.com/x/log.txt?x=175def47080000
> > kernel config: https://syzkaller.appspot.com/x/.config?x=5cea15779c42821c
> > dashboard link: https://syzkaller.appspot.com/bug?extid=775a3440817f74fddb8c
> > compiler: Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2
> > userspace arch: arm64
> >
> > Unfortunately, I don't have any reproducer for this issue yet.
> >
> > IMPORTANT: if you fix the issue, please add the following tag to the commit:
> > Reported-by: syzbot+775a3440817f74fddb8c@syzkaller.appspotmail.com
> >
> > Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
> > Mem abort info:
> > ESR = 0x0000000086000005
> > EC = 0x21: IABT (current EL), IL = 32 bits
> > SET = 0, FnV = 0
> > EA = 0, S1PTW = 0
> > FSC = 0x05: level 1 translation fault
> > user pgtable: 4k pages, 48-bit VAs, pgdp=00000001249cc000
> > [0000000000000000] pgd=080000012ee65003, p4d=080000012ee65003, pud=0000000000000000
> > Internal error: Oops: 86000005 [#1] PREEMPT SMP
> > Modules linked in:
> > CPU: 0 PID: 3044 Comm: syz-executor.0 Not tainted 6.0.0-rc2-syzkaller-16455-ga41a877bc12d #0
> > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/20/2022
> > pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
> > pc : 0x0
> > lr : folio_mark_dirty+0xbc/0x208 mm/page-writeback.c:2748
> > sp : ffff800012803830
> > x29: ffff800012803830 x28: ffff0000d02c8000 x27: 0000000000000009
> > x26: 0000000000000001 x25: 0000000000000a00 x24: 0000000000000080
> > x23: 0000000000000000 x22: ffff0000ef276c00 x21: 05ffc00000000007
> > x20: ffff0000f14b83b8 x19: fffffc00036409c0 x18: fffffffffffffff5
> > x17: ffff80000dd7a698 x16: ffff80000dbb8658 x15: 0000000000000000
> > x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000
> > x11: ff808000083e9814 x10: 0000000000000000 x9 : ffff8000083e9814
> > x8 : 0000000000000000 x7 : 0000000000000000 x6 : 0000000000000000
> > x5 : ffff0000d9028000 x4 : ffff0000d5c31000 x3 : ffff0000d9027f80
> > x2 : fffffffffffffff0 x1 : fffffc00036409c0 x0 : ffff0000f14b83b8
> > Call trace:
> > 0x0
> > set_page_dirty+0x38/0xbc mm/folio-compat.c:62

2363 void f2fs_update_meta_page(struct f2fs_sb_info *sbi,
2364 void *src, block_t blk_addr)
2365 {
2366 struct page *page = f2fs_grab_meta_page(sbi, blk_addr);

--> f2fs_grab_meta_page() gives a locked page by grab_cache_page().

2367
2368 memcpy(page_address(page), src, PAGE_SIZE);
2369 set_page_dirty(page);
2370 f2fs_put_page(page, 1);
2371 }

Is there a change in folio?

> > get_next_nat_page+0x198/0x300 fs/f2fs/node.c:154
> > __flush_nat_entry_set fs/f2fs/node.c:3005 [inline]
> > f2fs_flush_nat_entries+0x354/0x988 fs/f2fs/node.c:3109
> > f2fs_write_checkpoint+0x350/0x568 fs/f2fs/checkpoint.c:1667
> > f2fs_issue_checkpoint+0x1b0/0x234
> > f2fs_sync_fs+0x8c/0xc8 fs/f2fs/super.c:1651
> > sync_filesystem+0xe0/0x134 fs/sync.c:66
> > generic_shutdown_super+0x38/0x190 fs/super.c:474
> > kill_block_super+0x30/0x78 fs/super.c:1427
> > kill_f2fs_super+0x140/0x184 fs/f2fs/super.c:4544
> > deactivate_locked_super+0x70/0xd4 fs/super.c:332
> > deactivate_super+0xb8/0xbc fs/super.c:363
> > cleanup_mnt+0x1f8/0x234 fs/namespace.c:1186
> > __cleanup_mnt+0x20/0x30 fs/namespace.c:1193
> > task_work_run+0xc4/0x208 kernel/task_work.c:177
> > resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
> > do_notify_resume+0x174/0x1d0 arch/arm64/kernel/signal.c:1127
> > prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline]
> > exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline]
> > el0_svc+0x9c/0x150 arch/arm64/kernel/entry-common.c:625
> > el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:642
> > el0t_64_sync+0x18c/0x190
> > Code: bad PC value
> > ---[ end trace 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 syzkaller@googlegroups.com.
> >
> > syzbot will keep track of this issue. See:
> > https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

\
 
 \ /
  Last update: 2022-08-29 19:53    [W:0.054 / U:0.056 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site