[Android 5.4] KASAN: use-after-free Read in __ext4_iget (3)
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syzbot
Mar 13, 2025, 1:21:30 PM3/13/25
to syzkaller-a...@googlegroups.com
Hello,
syzbot found the following issue on:
HEAD commit: 6b07fcd94a6a Merge tag 'android12-5.4.290_r00' into androi..
git tree: android12-5.4
console+strace: https://syzkaller.appspot.com/x/log.txt?x=13403f8c580000
kernel config: https://syzkaller.appspot.com/x/.config?x=55297da5fb1e8eb8
dashboard link: https://syzkaller.appspot.com/bug?extid=2e888c41f43fbd593d7c
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=12e00fa8580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1644d874580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/24df6995dc4e/disk-6b07fcd9.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/9e3b4e1aaa60/vmlinux-6b07fcd9.xz
kernel image: https://storage.googleapis.com/syzbot-assets/26f34b81fa98/bzImage-6b07fcd9.xz
mounted in repro #1: https://storage.googleapis.com/syzbot-assets/a74d6697dfe6/mount_0.gz
fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=1244d874580000)
mounted in repro #2: https://storage.googleapis.com/syzbot-assets/a4726fa291c8/mount_1.gz
fsck result: OK (log: https://syzkaller.appspot.com/x/fsck.log?x=14e00fa8580000)
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+2e888c...@syzkaller.appspotmail.com
==================================================================
BUG: KASAN: use-after-free in check_igot_inode fs/ext4/inode.c:4953 [inline]
BUG: KASAN: use-after-free in __ext4_iget+0x384/0x4330 fs/ext4/inode.c:5001
Read of size 8 at addr ffff8881dcf92ad0 by task syz-executor300/634
CPU: 1 PID: 634 Comm: syz-executor300 Not tainted 5.4.290-syzkaller-00017-g6b07fcd94a6a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1d8/0x241 lib/dump_stack.c:118
print_address_description+0x8c/0x600 mm/kasan/report.c:384
__kasan_report+0xf3/0x120 mm/kasan/report.c:516
kasan_report+0x30/0x60 mm/kasan/common.c:653
check_igot_inode fs/ext4/inode.c:4953 [inline]
__ext4_iget+0x384/0x4330 fs/ext4/inode.c:5001
ext4_quota_enable fs/ext4/super.c:6056 [inline]
ext4_enable_quotas+0x528/0x940 fs/ext4/super.c:6092
ext4_fill_super+0x84f0/0x8d90 fs/ext4/super.c:4708
mount_bdev+0x267/0x370 fs/super.c:1428
legacy_get_tree+0xdf/0x170 fs/fs_context.c:648
vfs_get_tree+0x85/0x260 fs/super.c:1558
do_new_mount+0x292/0x570 fs/namespace.c:2850
do_mount+0x688/0xe10 fs/namespace.c:3170
ksys_mount+0xc2/0xf0 fs/namespace.c:3379
__do_sys_mount fs/namespace.c:3393 [inline]
__se_sys_mount fs/namespace.c:3390 [inline]
__x64_sys_mount+0xb1/0xc0 fs/namespace.c:3390
do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x5c/0xc1
RIP: 0033:0x7fb955bc38da
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 5e 04 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffdf3906f98 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffdf3906ff0 RCX: 00007fb955bc38da
RDX: 0000400000000180 RSI: 0000400000000000 RDI: 00007ffdf3906ff0
RBP: 0000400000000000 R08: 00007ffdf3907030 R09: 00000000000004fb
R10: 000000000021081e R11: 0000000000000206 R12: 0000400000000180
R13: 00007ffdf3907030 R14: 0000000000000501 R15: 00004000000001c0
Allocated by task 450:
save_stack mm/kasan/common.c:70 [inline]
set_track mm/kasan/common.c:78 [inline]
__kasan_kmalloc+0x171/0x210 mm/kasan/common.c:529
slab_post_alloc_hook mm/slab.h:584 [inline]
slab_alloc_node mm/slub.c:2829 [inline]
slab_alloc mm/slub.c:2837 [inline]
kmem_cache_alloc+0xd9/0x250 mm/slub.c:2842
f2fs_alloc_inode+0x22/0x3c0 fs/f2fs/super.c:1241
alloc_inode fs/inode.c:231 [inline]
iget_locked+0x143/0x790 fs/inode.c:1273
f2fs_iget+0x52/0x4cf0 fs/f2fs/inode.c:499
f2fs_fill_super+0x6909/0x8330 fs/f2fs/super.c:4071
mount_bdev+0x267/0x370 fs/super.c:1428
legacy_get_tree+0xdf/0x170 fs/fs_context.c:648
vfs_get_tree+0x85/0x260 fs/super.c:1558
do_new_mount+0x292/0x570 fs/namespace.c:2850
do_mount+0x688/0xe10 fs/namespace.c:3170
ksys_mount+0xc2/0xf0 fs/namespace.c:3379
__do_sys_mount fs/namespace.c:3393 [inline]
__se_sys_mount fs/namespace.c:3390 [inline]
__x64_sys_mount+0xb1/0xc0 fs/namespace.c:3390
do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x5c/0xc1
Freed by task 10:
save_stack mm/kasan/common.c:70 [inline]
set_track mm/kasan/common.c:78 [inline]
kasan_set_free_info mm/kasan/common.c:345 [inline]
__kasan_slab_free+0x1b5/0x270 mm/kasan/common.c:487
slab_free_hook mm/slub.c:1455 [inline]
slab_free_freelist_hook mm/slub.c:1494 [inline]
slab_free mm/slub.c:3080 [inline]
kmem_cache_free+0x10b/0x2c0 mm/slub.c:3096
__rcu_reclaim kernel/rcu/rcu.h:222 [inline]
rcu_do_batch+0x492/0xa00 kernel/rcu/tree.c:2167
rcu_core+0x4c8/0xcb0 kernel/rcu/tree.c:2387
__do_softirq+0x23b/0x6b7 kernel/softirq.c:292
The buggy address belongs to the object at ffff8881dcf92610
which belongs to the cache f2fs_inode_cache of size 1264
The buggy address is located 1216 bytes inside of
1264-byte region [ffff8881dcf92610, ffff8881dcf92b00)
The buggy address belongs to the page:
page:ffffea000773e400 refcount:1 mapcount:0 mapping:ffff8881f0fcc500 index:0xffff8881dcf90570 compound_mapcount: 0
flags: 0x8000000000010200(slab|head)
raw: 8000000000010200 0000000000000000 0000000100000001 ffff8881f0fcc500
raw: ffff8881dcf90570 0000000080170011 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Reclaimable, gfp_mask 0xd2050(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_RECLAIMABLE)
set_page_owner include/linux/page_owner.h:31 [inline]
post_alloc_hook mm/page_alloc.c:2165 [inline]
prep_new_page+0x18f/0x370 mm/page_alloc.c:2171
get_page_from_freelist+0x2d13/0x2d90 mm/page_alloc.c:3794
__alloc_pages_nodemask+0x393/0x840 mm/page_alloc.c:4893
alloc_slab_page+0x39/0x3c0 mm/slub.c:343
allocate_slab mm/slub.c:1683 [inline]
new_slab+0x97/0x440 mm/slub.c:1749
new_slab_objects mm/slub.c:2505 [inline]
___slab_alloc+0x2fe/0x490 mm/slub.c:2667
__slab_alloc+0x62/0xa0 mm/slub.c:2707
slab_alloc_node mm/slub.c:2792 [inline]
slab_alloc mm/slub.c:2837 [inline]
kmem_cache_alloc+0x109/0x250 mm/slub.c:2842
f2fs_alloc_inode+0x22/0x3c0 fs/f2fs/super.c:1241
alloc_inode fs/inode.c:231 [inline]
iget_locked+0x143/0x790 fs/inode.c:1273
f2fs_iget+0x52/0x4cf0 fs/f2fs/inode.c:499
f2fs_fill_super+0x4d1b/0x8330 fs/f2fs/super.c:3963
mount_bdev+0x267/0x370 fs/super.c:1428
legacy_get_tree+0xdf/0x170 fs/fs_context.c:648
vfs_get_tree+0x85/0x260 fs/super.c:1558
do_new_mount+0x292/0x570 fs/namespace.c:2850
page_owner free stack trace missing
Memory state around the buggy address:
ffff8881dcf92980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8881dcf92a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8881dcf92a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8881dcf92b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff8881dcf92b80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================
EXT4-fs warning (device loop2): ext4_enable_quotas:6100: Failed to enable quota tracking (type=0, err=-13, ino=3). Please run e2fsck to fix.
EXT4-fs (loop2): mount failed
---
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 syzk...@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.
If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)
If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
syzbot found the following issue on:
HEAD commit: 6b07fcd94a6a Merge tag 'android12-5.4.290_r00' into androi..
git tree: android12-5.4
console+strace: https://syzkaller.appspot.com/x/log.txt?x=13403f8c580000
kernel config: https://syzkaller.appspot.com/x/.config?x=55297da5fb1e8eb8
dashboard link: https://syzkaller.appspot.com/bug?extid=2e888c41f43fbd593d7c
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=12e00fa8580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1644d874580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/24df6995dc4e/disk-6b07fcd9.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/9e3b4e1aaa60/vmlinux-6b07fcd9.xz
kernel image: https://storage.googleapis.com/syzbot-assets/26f34b81fa98/bzImage-6b07fcd9.xz
mounted in repro #1: https://storage.googleapis.com/syzbot-assets/a74d6697dfe6/mount_0.gz
fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=1244d874580000)
mounted in repro #2: https://storage.googleapis.com/syzbot-assets/a4726fa291c8/mount_1.gz
fsck result: OK (log: https://syzkaller.appspot.com/x/fsck.log?x=14e00fa8580000)
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+2e888c...@syzkaller.appspotmail.com
==================================================================
BUG: KASAN: use-after-free in check_igot_inode fs/ext4/inode.c:4953 [inline]
BUG: KASAN: use-after-free in __ext4_iget+0x384/0x4330 fs/ext4/inode.c:5001
Read of size 8 at addr ffff8881dcf92ad0 by task syz-executor300/634
CPU: 1 PID: 634 Comm: syz-executor300 Not tainted 5.4.290-syzkaller-00017-g6b07fcd94a6a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1d8/0x241 lib/dump_stack.c:118
print_address_description+0x8c/0x600 mm/kasan/report.c:384
__kasan_report+0xf3/0x120 mm/kasan/report.c:516
kasan_report+0x30/0x60 mm/kasan/common.c:653
check_igot_inode fs/ext4/inode.c:4953 [inline]
__ext4_iget+0x384/0x4330 fs/ext4/inode.c:5001
ext4_quota_enable fs/ext4/super.c:6056 [inline]
ext4_enable_quotas+0x528/0x940 fs/ext4/super.c:6092
ext4_fill_super+0x84f0/0x8d90 fs/ext4/super.c:4708
mount_bdev+0x267/0x370 fs/super.c:1428
legacy_get_tree+0xdf/0x170 fs/fs_context.c:648
vfs_get_tree+0x85/0x260 fs/super.c:1558
do_new_mount+0x292/0x570 fs/namespace.c:2850
do_mount+0x688/0xe10 fs/namespace.c:3170
ksys_mount+0xc2/0xf0 fs/namespace.c:3379
__do_sys_mount fs/namespace.c:3393 [inline]
__se_sys_mount fs/namespace.c:3390 [inline]
__x64_sys_mount+0xb1/0xc0 fs/namespace.c:3390
do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x5c/0xc1
RIP: 0033:0x7fb955bc38da
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 5e 04 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffdf3906f98 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffdf3906ff0 RCX: 00007fb955bc38da
RDX: 0000400000000180 RSI: 0000400000000000 RDI: 00007ffdf3906ff0
RBP: 0000400000000000 R08: 00007ffdf3907030 R09: 00000000000004fb
R10: 000000000021081e R11: 0000000000000206 R12: 0000400000000180
R13: 00007ffdf3907030 R14: 0000000000000501 R15: 00004000000001c0
Allocated by task 450:
save_stack mm/kasan/common.c:70 [inline]
set_track mm/kasan/common.c:78 [inline]
__kasan_kmalloc+0x171/0x210 mm/kasan/common.c:529
slab_post_alloc_hook mm/slab.h:584 [inline]
slab_alloc_node mm/slub.c:2829 [inline]
slab_alloc mm/slub.c:2837 [inline]
kmem_cache_alloc+0xd9/0x250 mm/slub.c:2842
f2fs_alloc_inode+0x22/0x3c0 fs/f2fs/super.c:1241
alloc_inode fs/inode.c:231 [inline]
iget_locked+0x143/0x790 fs/inode.c:1273
f2fs_iget+0x52/0x4cf0 fs/f2fs/inode.c:499
f2fs_fill_super+0x6909/0x8330 fs/f2fs/super.c:4071
mount_bdev+0x267/0x370 fs/super.c:1428
legacy_get_tree+0xdf/0x170 fs/fs_context.c:648
vfs_get_tree+0x85/0x260 fs/super.c:1558
do_new_mount+0x292/0x570 fs/namespace.c:2850
do_mount+0x688/0xe10 fs/namespace.c:3170
ksys_mount+0xc2/0xf0 fs/namespace.c:3379
__do_sys_mount fs/namespace.c:3393 [inline]
__se_sys_mount fs/namespace.c:3390 [inline]
__x64_sys_mount+0xb1/0xc0 fs/namespace.c:3390
do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x5c/0xc1
Freed by task 10:
save_stack mm/kasan/common.c:70 [inline]
set_track mm/kasan/common.c:78 [inline]
kasan_set_free_info mm/kasan/common.c:345 [inline]
__kasan_slab_free+0x1b5/0x270 mm/kasan/common.c:487
slab_free_hook mm/slub.c:1455 [inline]
slab_free_freelist_hook mm/slub.c:1494 [inline]
slab_free mm/slub.c:3080 [inline]
kmem_cache_free+0x10b/0x2c0 mm/slub.c:3096
__rcu_reclaim kernel/rcu/rcu.h:222 [inline]
rcu_do_batch+0x492/0xa00 kernel/rcu/tree.c:2167
rcu_core+0x4c8/0xcb0 kernel/rcu/tree.c:2387
__do_softirq+0x23b/0x6b7 kernel/softirq.c:292
The buggy address belongs to the object at ffff8881dcf92610
which belongs to the cache f2fs_inode_cache of size 1264
The buggy address is located 1216 bytes inside of
1264-byte region [ffff8881dcf92610, ffff8881dcf92b00)
The buggy address belongs to the page:
page:ffffea000773e400 refcount:1 mapcount:0 mapping:ffff8881f0fcc500 index:0xffff8881dcf90570 compound_mapcount: 0
flags: 0x8000000000010200(slab|head)
raw: 8000000000010200 0000000000000000 0000000100000001 ffff8881f0fcc500
raw: ffff8881dcf90570 0000000080170011 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Reclaimable, gfp_mask 0xd2050(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_RECLAIMABLE)
set_page_owner include/linux/page_owner.h:31 [inline]
post_alloc_hook mm/page_alloc.c:2165 [inline]
prep_new_page+0x18f/0x370 mm/page_alloc.c:2171
get_page_from_freelist+0x2d13/0x2d90 mm/page_alloc.c:3794
__alloc_pages_nodemask+0x393/0x840 mm/page_alloc.c:4893
alloc_slab_page+0x39/0x3c0 mm/slub.c:343
allocate_slab mm/slub.c:1683 [inline]
new_slab+0x97/0x440 mm/slub.c:1749
new_slab_objects mm/slub.c:2505 [inline]
___slab_alloc+0x2fe/0x490 mm/slub.c:2667
__slab_alloc+0x62/0xa0 mm/slub.c:2707
slab_alloc_node mm/slub.c:2792 [inline]
slab_alloc mm/slub.c:2837 [inline]
kmem_cache_alloc+0x109/0x250 mm/slub.c:2842
f2fs_alloc_inode+0x22/0x3c0 fs/f2fs/super.c:1241
alloc_inode fs/inode.c:231 [inline]
iget_locked+0x143/0x790 fs/inode.c:1273
f2fs_iget+0x52/0x4cf0 fs/f2fs/inode.c:499
f2fs_fill_super+0x4d1b/0x8330 fs/f2fs/super.c:3963
mount_bdev+0x267/0x370 fs/super.c:1428
legacy_get_tree+0xdf/0x170 fs/fs_context.c:648
vfs_get_tree+0x85/0x260 fs/super.c:1558
do_new_mount+0x292/0x570 fs/namespace.c:2850
page_owner free stack trace missing
Memory state around the buggy address:
ffff8881dcf92980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8881dcf92a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8881dcf92a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8881dcf92b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff8881dcf92b80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================
EXT4-fs warning (device loop2): ext4_enable_quotas:6100: Failed to enable quota tracking (type=0, err=-13, ino=3). Please run e2fsck to fix.
EXT4-fs (loop2): mount failed
---
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 syzk...@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.
If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)
If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
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