Message-ID: <0000000000007f6b6e06077ba8fa@google.com>
Date:   Wed, 11 Oct 2023 19:25:49 -0700
From:   syzbot <syzbot+47f3372b693d7f62b8ae@...kaller.appspotmail.com>
To:     adilger.kernel@...ger.ca, jack@...e.com,
        linux-ext4@...r.kernel.org, linux-fsdevel@...r.kernel.org,
        linux-kernel@...r.kernel.org, syzkaller-bugs@...glegroups.com,
        tytso@....edu
Subject: [syzbot] [ext4?] KASAN: wild-memory-access Read in read_block_bitmap

Hello,

syzbot found the following issue on:

HEAD commit:    19af4a4ed414 Merge branch 'for-next/core', remote-tracking..
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=137ade41680000
kernel config:  https://syzkaller.appspot.com/x/.config?x=80eedef55cd21fa4
dashboard link: https://syzkaller.appspot.com/bug?extid=47f3372b693d7f62b8ae
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=1035f9ce680000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=132439c9680000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/702d996331e0/disk-19af4a4e.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/2a48ce0aeb32/vmlinux-19af4a4e.xz
kernel image: https://storage.googleapis.com/syzbot-assets/332eb4a803d2/Image-19af4a4e.gz.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/9ab1853e4248/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+47f3372b693d7f62b8ae@...kaller.appspotmail.com

EXT2-fs (loop0): error: ext2_free_branches: Read failure, inode=16, block=1669132791
EXT2-fs (loop0): error: ext2_free_branches: Read failure, inode=16, block=262144
==================================================================
BUG: KASAN: wild-memory-access in generic_test_bit include/asm-generic/bitops/generic-non-atomic.h:128 [inline]
BUG: KASAN: wild-memory-access in test_bit_le include/asm-generic/bitops/le.h:21 [inline]
BUG: KASAN: wild-memory-access in ext2_valid_block_bitmap fs/ext2/balloc.c:86 [inline]
BUG: KASAN: wild-memory-access in read_block_bitmap+0x338/0x628 fs/ext2/balloc.c:153
Read of size 8 at addr 1fff00018751cff8 by task syz-executor221/6316

CPU: 1 PID: 6316 Comm: syz-executor221 Not tainted 6.6.0-rc4-syzkaller-g19af4a4ed414 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023
Call trace:
 dump_backtrace+0x1b8/0x1e4 arch/arm64/kernel/stacktrace.c:233
 show_stack+0x2c/0x44 arch/arm64/kernel/stacktrace.c:240
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd0/0x124 lib/dump_stack.c:106
 print_report+0xe4/0x514 mm/kasan/report.c:478
 kasan_report+0xd8/0x138 mm/kasan/report.c:588
 __asan_report_load8_noabort+0x20/0x2c mm/kasan/report_generic.c:381
 generic_test_bit include/asm-generic/bitops/generic-non-atomic.h:128 [inline]
 test_bit_le include/asm-generic/bitops/le.h:21 [inline]
 ext2_valid_block_bitmap fs/ext2/balloc.c:86 [inline]
 read_block_bitmap+0x338/0x628 fs/ext2/balloc.c:153
 ext2_free_blocks+0x284/0x998 fs/ext2/balloc.c:514
 ext2_free_data fs/ext2/inode.c:1102 [inline]
 ext2_free_branches+0x2f4/0x3c4 fs/ext2/inode.c:1159
 ext2_free_branches+0x180/0x3c4 fs/ext2/inode.c:1150
 ext2_free_branches+0x180/0x3c4 fs/ext2/inode.c:1150
 __ext2_truncate_blocks+0x9a8/0xd00 fs/ext2/inode.c:1233
 ext2_setsize fs/ext2/inode.c:1291 [inline]
 ext2_setattr+0x774/0xa44 fs/ext2/inode.c:1661
 notify_change+0x9d4/0xc8c fs/attr.c:499
 do_truncate+0x1c0/0x28c fs/open.c:66
 handle_truncate fs/namei.c:3298 [inline]
 do_open fs/namei.c:3643 [inline]
 path_openat+0x2130/0x27f8 fs/namei.c:3796
 do_filp_open+0x1bc/0x3cc fs/namei.c:3823
 do_sys_openat2+0x124/0x1b8 fs/open.c:1422
 do_sys_open fs/open.c:1437 [inline]
 __do_sys_openat fs/open.c:1453 [inline]
 __se_sys_openat fs/open.c:1448 [inline]
 __arm64_sys_openat+0x1f0/0x240 fs/open.c:1448
 __invoke_syscall arch/arm64/kernel/syscall.c:37 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155
 el0_svc+0x58/0x16c arch/arm64/kernel/entry-common.c:678
 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696
 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:595
==================================================================
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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