[v5.15] KASAN: use-after-free Read in ext2_valid_block_bitmap

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 1edcec18cfb7 Linux 5.15.134
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=171eb9e9680000
kernel config: https://syzkaller.appspot.com/x/.config?x=307e255fc1f90f62
dashboard link: https://syzkaller.appspot.com/bug?extid=050dcfde88ab2b685d71
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/6ac27b2e493b/disk-1edcec18.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/090267cb6a2a/vmlinux-1edcec18.xz
kernel image: https://storage.googleapis.com/syzbot-assets/aec98b8f8ab7/Image-1edcec18.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+050dcf...@syzkaller.appspotmail.com

EXT2-fs (loop5): error: ext2_free_branches: Read failure, inode=16, block=1669132791
EXT2-fs (loop5): error: ext2_free_branches: Read failure, inode=16, block=262144
==================================================================
BUG: KASAN: use-after-free in arch_test_bit include/asm-generic/bitops/non-atomic.h:118 [inline]
BUG: KASAN: use-after-free in test_bit_le include/asm-generic/bitops/le.h:85 [inline]
BUG: KASAN: use-after-free in ext2_valid_block_bitmap+0x10c/0x2e0 fs/ext2/balloc.c:88
Read of size 8 at addr ffff000127b29ff8 by task syz-executor.5/10395

CPU: 0 PID: 10395 Comm: syz-executor.5 Not tainted 5.15.134-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023
Call trace:
dump_backtrace+0x0/0x530 arch/arm64/kernel/stacktrace.c:152
show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106
print_address_description+0x7c/0x3f0 mm/kasan/report.c:248
__kasan_report mm/kasan/report.c:434 [inline]
kasan_report+0x174/0x1e4 mm/kasan/report.c:451
__asan_report_load8_noabort+0x44/0x50 mm/kasan/report_generic.c:309
arch_test_bit include/asm-generic/bitops/non-atomic.h:118 [inline]
test_bit_le include/asm-generic/bitops/le.h:85 [inline]
ext2_valid_block_bitmap+0x10c/0x2e0 fs/ext2/balloc.c:88
read_block_bitmap+0x294/0x340 fs/ext2/balloc.c:154
ext2_free_blocks+0x280/0xa38 fs/ext2/balloc.c:515
ext2_free_data fs/ext2/inode.c:1121 [inline]
ext2_free_branches+0x2f4/0x3c4 fs/ext2/inode.c:1178
ext2_free_branches+0x180/0x3c4 fs/ext2/inode.c:1169
ext2_free_branches+0x180/0x3c4 fs/ext2/inode.c:1169
__ext2_truncate_blocks+0x9a8/0xd00 fs/ext2/inode.c:1252
ext2_setsize fs/ext2/inode.c:1314 [inline]
ext2_setattr+0x658/0x904 fs/ext2/inode.c:1692
notify_change+0xa34/0xcf8 fs/attr.c:505
do_truncate+0x1c0/0x28c fs/open.c:65
handle_truncate fs/namei.c:3195 [inline]
do_open fs/namei.c:3542 [inline]
path_openat+0x20e8/0x26f0 fs/namei.c:3672
do_filp_open+0x1a8/0x3b4 fs/namei.c:3699
do_sys_openat2+0x128/0x3d8 fs/open.c:1211
do_sys_open fs/open.c:1227 [inline]
__do_sys_openat fs/open.c:1243 [inline]
__se_sys_openat fs/open.c:1238 [inline]
__arm64_sys_openat+0x1f0/0x240 fs/open.c:1238
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:596
el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:614
el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

The buggy address belongs to the page:
page:0000000054fd88a4 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x167b29
flags: 0x5ffc00000000000(node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000000000 fffffc00049eca48 fffffc00049eca48 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ffff000127b29e80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff000127b29f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff000127b29f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
^
ffff000127b2a000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff000127b2a080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
EXT2-fs (loop5): error: ext2_valid_block_bitmap: Invalid block bitmap - block_group = 0, block = 0
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks in system zones - Block = 3, count = 3
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks not in datazone - block = 983269, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks not in datazone - block = 589827, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks not in datazone - block = 2185560079, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks not in datazone - block = 18346, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks in system zones - Block = 2, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks not in datazone - block = 33261, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: bit already cleared for block 100
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks not in datazone - block = 1669132791, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks not in datazone - block = 1669132791, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: bit already cleared for block 64
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks not in datazone - block = 65536, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks not in datazone - block = 268435456, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks not in datazone - block = 1, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks not in datazone - block = 1803188595, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks not in datazone - block = 1701604449, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks not in datazone - block = 2054779762, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks not in datazone - block = 1819042155, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks not in datazone - block = 7565925, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks not in datazone - block = 1937768448, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks not in datazone - block = 1634433657, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks not in datazone - block = 1919249516, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks not in datazone - block = 1803188595, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks not in datazone - block = 1701604449, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks not in datazone - block = 2054779762, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks not in datazone - block = 1819042155, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks not in datazone - block = 2037609061, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks not in datazone - block = 1818323834, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks not in datazone - block = 3133565699, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks not in datazone - block = 327680, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks not in datazone - block = 150994944, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks not in datazone - block = 2683928664, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks not in datazone - block = 2683928664, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks not in datazone - block = 2683928664, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks not in datazone - block = 1669132791, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks not in datazone - block = 2683928664, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks not in datazone - block = 3925999616, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks not in datazone - block = 3409668, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: bit already cleared for block 40
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks not in datazone - block = 1635017060, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks not in datazone - block = 1936876908, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks not in datazone - block = 1634433657, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks not in datazone - block = 1919249516, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks not in datazone - block = 1803188595, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks not in datazone - block = 1701604449, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks not in datazone - block = 2054779762, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks not in datazone - block = 1819042155, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks not in datazone - block = 2037609061, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks not in datazone - block = 1818323834, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks not in datazone - block = 1936876908, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: bit already cleared for block 9
EXT2-fs (loop5): error: ext2_free_blocks: bit already cleared for block 13
EXT2-fs (loop5): error: ext2_free_blocks: bit already cleared for block 32
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks not in datazone - block = 163928, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks not in datazone - block = 2683895808, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks not in datazone - block = 1669132790, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks not in datazone - block = 131072, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks in system zones - Block = 5, count = 1
EXT2-fs (loop5): error: ext2_free_blocks: Freeing blocks in system zones - Block = 5, count = 1
EXT2-fs (loop5): error: ext2_free_branches: Read failure, inode=16, block=16777216


---
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[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: 02e21884dcf2 Linux 5.15.135
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=16c2aec9680000
kernel config: https://syzkaller.appspot.com/x/.config?x=f681318e2cd0ce40

dashboard link: https://syzkaller.appspot.com/bug?extid=050dcfde88ab2b685d71
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12c870c1680000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=167428c5680000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/1e72b59201a3/disk-02e21884.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/d841863b4e66/vmlinux-02e21884.xz
kernel image: https://storage.googleapis.com/syzbot-assets/c0703f8945b1/Image-02e21884.gz.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/025c0f99204f/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+050dcf...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: use-after-free in arch_test_bit include/asm-generic/bitops/non-atomic.h:118 [inline]
BUG: KASAN: use-after-free in test_bit_le include/asm-generic/bitops/le.h:85 [inline]
BUG: KASAN: use-after-free in ext2_valid_block_bitmap+0x10c/0x2e0 fs/ext2/balloc.c:88

Read of size 8 at addr ffff0000fd414ff8 by task syz-executor372/3977

CPU: 1 PID: 3977 Comm: syz-executor372 Not tainted 5.15.135-syzkaller #0

page:000000005c4593eb refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x13d414
flags: 0x5ffc00000000000(node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000000000 fffffc0003f50508 fffffc0003f50508 0000000000000000

raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:

ffff0000fd414e80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff0000fd414f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff0000fd414f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
^
ffff0000fd415000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff0000fd415080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
EXT2-fs (loop0): error: ext2_valid_block_bitmap: Invalid block bitmap - block_group = 0, block = 0
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks in system zones - Block = 3, count = 3
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks not in datazone - block = 983269, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks not in datazone - block = 589827, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks not in datazone - block = 2185560079, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks not in datazone - block = 18346, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks in system zones - Block = 2, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks not in datazone - block = 33261, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: bit already cleared for block 100
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks not in datazone - block = 1669132791, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks not in datazone - block = 1669132791, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: bit already cleared for block 64
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks not in datazone - block = 65536, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks not in datazone - block = 268435456, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks not in datazone - block = 1, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks not in datazone - block = 1803188595, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks not in datazone - block = 1701604449, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks not in datazone - block = 2054779762, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks not in datazone - block = 1819042155, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks not in datazone - block = 7565925, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks not in datazone - block = 1937768448, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks not in datazone - block = 1634433657, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks not in datazone - block = 1919249516, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks not in datazone - block = 1803188595, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks not in datazone - block = 1701604449, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks not in datazone - block = 2054779762, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks not in datazone - block = 1819042155, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks not in datazone - block = 2037609061, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks not in datazone - block = 1818323834, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks not in datazone - block = 3133565699, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks not in datazone - block = 327680, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks not in datazone - block = 150994944, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks not in datazone - block = 2683928664, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks not in datazone - block = 2683928664, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks not in datazone - block = 2683928664, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks not in datazone - block = 1669132791, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks not in datazone - block = 2683928664, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks not in datazone - block = 3925999616, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks not in datazone - block = 3409668, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: bit already cleared for block 40
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks not in datazone - block = 1635017060, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks not in datazone - block = 1936876908, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks not in datazone - block = 1634433657, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks not in datazone - block = 1919249516, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks not in datazone - block = 1803188595, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks not in datazone - block = 1701604449, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks not in datazone - block = 2054779762, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks not in datazone - block = 1819042155, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks not in datazone - block = 2037609061, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks not in datazone - block = 1818323834, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks not in datazone - block = 1936876908, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: bit already cleared for block 9
EXT2-fs (loop0): error: ext2_free_blocks: bit already cleared for block 13
EXT2-fs (loop0): error: ext2_free_blocks: bit already cleared for block 32
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks not in datazone - block = 163928, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks not in datazone - block = 2683895808, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks not in datazone - block = 1669132790, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks not in datazone - block = 131072, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks in system zones - Block = 5, count = 1
EXT2-fs (loop0): error: ext2_free_blocks: Freeing blocks in system zones - Block = 5, count = 1
EXT2-fs (loop0): error: ext2_free_branches: Read failure, inode=16, block=16777216


---
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