[syzbot] KASAN: use-after-free Read in dbJoin

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syzbot

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Oct 10, 2022, 3:35:40 AM10/10/22
to jfs-dis...@lists.sourceforge.net, linux-...@vger.kernel.org, sha...@kernel.org, syzkall...@googlegroups.com
Hello,

syzbot found the following issue on:

HEAD commit: aaa11ce2ffc8 Add linux-next specific files for 20220923
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=10a9b134880000
kernel config: https://syzkaller.appspot.com/x/.config?x=186d1ff305f10294
dashboard link: https://syzkaller.appspot.com/bug?extid=667a6d667592227b1452
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/95c7bf83c07e/disk-aaa11ce2.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/b161cd56a7a3/vmlinux-aaa11ce2.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+667a6d...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: use-after-free in dbJoin+0x23b/0x240 fs/jfs/jfs_dmap.c:2772
Read of size 1 at addr ffff88817cbdfa4c by task jfsCommit/123

CPU: 0 PID: 123 Comm: jfsCommit Not tainted 6.0.0-rc6-next-20220923-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
print_address_description mm/kasan/report.c:284 [inline]
print_report+0x15e/0x45d mm/kasan/report.c:395
kasan_report+0xbb/0x1f0 mm/kasan/report.c:495
dbJoin+0x23b/0x240 fs/jfs/jfs_dmap.c:2772
dbFreeBits+0x15d/0x8c0 fs/jfs/jfs_dmap.c:2305
dbFreeDmap+0x61/0x1a0 fs/jfs/jfs_dmap.c:2054
dbFree+0x250/0x540 fs/jfs/jfs_dmap.c:379
txFreeMap+0x8f1/0xd70 fs/jfs/jfs_txnmgr.c:2529
txUpdateMap+0x3cd/0xc50 fs/jfs/jfs_txnmgr.c:2325
txLazyCommit fs/jfs/jfs_txnmgr.c:2659 [inline]
jfs_lazycommit+0x5bb/0xaa0 fs/jfs/jfs_txnmgr.c:2727
kthread+0x2e4/0x3a0 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
</TASK>

The buggy address belongs to the physical page:
page:ffffea0005f2f7c0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x17cbdf
flags: 0x57ff00000000000(node=1|zone=2|lastcpupid=0x7ff)
raw: 057ff00000000000 ffffea0005f2f7c8 ffffea0005f2f7c8 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner info is not present (never set?)

Memory state around the buggy address:
ffff88817cbdf900: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff88817cbdf980: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88817cbdfa00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
^
ffff88817cbdfa80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff88817cbdfb00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================


---
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syzbot

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Nov 6, 2022, 3:02:47 PM11/6/22
to jfs-dis...@lists.sourceforge.net, linux-...@vger.kernel.org, sha...@kernel.org, syzkall...@googlegroups.com
syzbot has found a reproducer for the following issue on:

HEAD commit: b208b9fbbcba Merge tag 'arm64-fixes' of git://git.kernel.o..
git tree: upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=162c2866880000
kernel config: https://syzkaller.appspot.com/x/.config?x=f7e100ed8aaa828e
dashboard link: https://syzkaller.appspot.com/bug?extid=667a6d667592227b1452
compiler: Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12f7ffb1880000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17f9a066880000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/92fde6d92d82/disk-b208b9fb.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/ae3dbdb3faf8/vmlinux-b208b9fb.xz
kernel image: https://storage.googleapis.com/syzbot-assets/bbf4da09683c/bzImage-b208b9fb.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/69e8cbb81983/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+667a6d...@syzkaller.appspotmail.com

================================================================================
UBSAN: array-index-out-of-bounds in fs/jfs/jfs_dmap.c:2745:24
index 1426063360 is out of range for type 's8 [1365]'
CPU: 0 PID: 122 Comm: jfsCommit Not tainted 6.1.0-rc3-syzkaller-00288-gb208b9fbbcba #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1b1/0x28e lib/dump_stack.c:106
ubsan_epilogue lib/ubsan.c:151 [inline]
__ubsan_handle_out_of_bounds+0xdb/0x130 lib/ubsan.c:283
dbJoin+0x2c7/0x2f0 fs/jfs/jfs_dmap.c:2745
dbFreeBits+0x50d/0xd40 fs/jfs/jfs_dmap.c:2305
dbFreeDmap fs/jfs/jfs_dmap.c:2054 [inline]
dbFree+0x35e/0x660 fs/jfs/jfs_dmap.c:379
txFreeMap+0x97c/0xd70 fs/jfs/jfs_txnmgr.c:2510
xtTruncate+0xe74/0x32d0 fs/jfs/jfs_xtree.c:2467
jfs_free_zero_link+0x3f5/0x680 fs/jfs/namei.c:758
jfs_evict_inode+0x35a/0x440 fs/jfs/inode.c:153
evict+0x2a4/0x620 fs/inode.c:664
txUpdateMap+0x8eb/0xaa0 fs/jfs/jfs_txnmgr.c:2362
txLazyCommit fs/jfs/jfs_txnmgr.c:2659 [inline]
jfs_lazycommit+0x488/0xb80 fs/jfs/jfs_txnmgr.c:2727
kthread+0x266/0x300 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
</TASK>
================================================================================

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