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KASAN: use-after-free Read in ext4_get_inode_usage

Status: upstream: reported C repro on 2026/05/15 18:41
Reported-by: syzbot+5a4cb69d50e0f4dc32e9@syzkaller.appspotmail.com
First crash: 59d, last: 4d20h
▶ ▼ Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-5-15 KASAN: slab-out-of-bounds Read in ext4_get_inode_usage origin:upstream 19 C 11 3d15h 58d 0/2 upstream: reported C repro on 2026/05/16 23:51
linux-5.15 KASAN: use-after-free Read in ext4_get_inode_usage origin:upstream 19 C 2 9d02h 58d 0/3 upstream: reported C repro on 2026/05/17 01:53
android-6-1 KASAN: use-after-free Read in ext4_get_inode_usage 19 C 4 4d19h 4d21h 0/2 upstream: reported C repro on 2026/07/09 15:06
▶ ▼ Last patch testing requests (6)
Created Duration User Patch Repo Result
2026/07/03 07:57 16m retest repro android13-5.10-lts log
2026/06/15 12:15 15m retest repro android13-5.10-lts log
2026/06/15 12:15 12m retest repro android13-5.10-lts log
2026/06/15 12:15 23m retest repro android13-5.10-lts log
2026/06/15 12:15 22m retest repro android13-5.10-lts log
2026/06/15 12:15 12m retest repro android13-5.10-lts log
▶ ▼ Fix bisection attempts (1)
Created Duration User Patch Repo Result
2026/06/18 07:35 1h31m bisect fix android13-5.10-lts OK (0) job log log

Sample crash report:
EXT4-fs (loop2): mounted filesystem without journal. Opts: ,errors=continue
EXT4-fs error (device loop2): xattr_find_entry:297: inode #15: comm syz.2.17: corrupted xattr entries
==================================================================
BUG: KASAN: use-after-free in ext4_get_inode_usage+0x371/0x520 fs/ext4/xattr.c:819
Read of size 4 at addr ffff88812776e000 by task syz.2.17/393

CPU: 0 PID: 393 Comm: syz.2.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
 __dump_stack+0x21/0x24 lib/dump_stack.c:77
 dump_stack_lvl+0x1a7/0x208 lib/dump_stack.c:118
 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:435 [inline]
 kasan_report+0x100/0x140 mm/kasan/report.c:452
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:308
 ext4_get_inode_usage+0x371/0x520 fs/ext4/xattr.c:819
 __dquot_transfer+0x192/0x2250 fs/quota/dquot.c:2039
 dquot_transfer+0x2f3/0x470 fs/quota/dquot.c:2191
 ext4_setattr+0x73d/0x1980 fs/ext4/inode.c:5577
 notify_change+0xab5/0xe40 fs/attr.c:410
 chown_common+0x2f9/0x4a0 fs/open.c:675
 do_fchownat+0x147/0x240 fs/open.c:705
 __do_sys_lchown fs/open.c:730 [inline]
 __se_sys_lchown fs/open.c:728 [inline]
 __x64_sys_lchown+0x85/0x90 fs/open.c:728
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f9c3f344e59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff526ab838 EFLAGS: 00000246 ORIG_RAX: 000000000000005e
RAX: ffffffffffffffda RBX: 00007f9c3f5ccfa0 RCX: 00007f9c3f344e59
RDX: 0000000000000000 RSI: 00000000000000ff RDI: 00002000000004c0
RBP: 00007f9c3f3dae6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9c3f5ccfac R14: 00007f9c3f5ccfa0 R15: 00007f9c3f5ccfa0

The buggy address belongs to the page:
page:ffffea00049ddb80 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x12776e
flags: 0x4000000000000000()
raw: 4000000000000000 ffffea000496e008 ffffea00049dfdc8 0000000000000000
raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 0, migratetype Movable, gfp_mask 0x8100dca(GFP_HIGHUSER_MOVABLE|__GFP_ZERO|0x8000000), pid 300, ts 27788775618, free_ts 27800647929
 set_page_owner include/linux/page_owner.h:35 [inline]
 post_alloc_hook mm/page_alloc.c:2456 [inline]
 prep_new_page+0x176/0x190 mm/page_alloc.c:2462
 get_page_from_freelist+0x225f/0x23f0 mm/page_alloc.c:4254
 __alloc_pages_nodemask+0x29a/0x640 mm/page_alloc.c:5384
 __alloc_pages include/linux/gfp.h:544 [inline]
 __alloc_pages_node include/linux/gfp.h:557 [inline]
 alloc_pages_node include/linux/gfp.h:571 [inline]
 alloc_pages include/linux/gfp.h:590 [inline]
 do_anonymous_page mm/memory.c:3963 [inline]
 handle_pte_fault+0x153b/0x3910 mm/memory.c:4795
 __handle_mm_fault mm/memory.c:4953 [inline]
 handle_mm_fault+0xf86/0x1720 mm/memory.c:5367
 do_user_addr_fault+0x576/0xe20 arch/x86/mm/fault.c:1343
 handle_page_fault arch/x86/mm/fault.c:1436 [inline]
 exc_page_fault+0x5a/0xc0 arch/x86/mm/fault.c:1492
 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:571
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:28 [inline]
 free_pages_prepare mm/page_alloc.c:1349 [inline]
 free_pcp_prepare mm/page_alloc.c:1421 [inline]
 free_unref_page_prepare+0x2b7/0x2d0 mm/page_alloc.c:3336
 free_unref_page_list+0x129/0x9c0 mm/page_alloc.c:3443
 release_pages+0xe41/0xe90 mm/swap.c:1103
 pagevec_lru_move_fn+0x193/0x210 mm/swap.c:235
 __pagevec_lru_add mm/swap.c:1217 [inline]
 lru_add_drain_cpu+0x10a/0x6e0 mm/swap.c:700
 lru_add_drain+0x3d/0xc0 mm/swap.c:832
 unmap_region+0xf8/0x3c0 mm/mmap.c:2789
 __do_munmap+0x63c/0x850 mm/mmap.c:3041
 do_munmap mm/mmap.c:3052 [inline]
 munmap_vma_range mm/mmap.c:639 [inline]
 __mmap_region mm/mmap.c:1834 [inline]
 mmap_region+0x8a2/0x19c0 mm/mmap.c:3075
 do_mmap+0x85f/0xf50 mm/mmap.c:1661
 vm_mmap_pgoff+0x1f4/0x350 mm/util.c:543
 ksys_mmap_pgoff+0x16f/0x1e0 mm/mmap.c:1712
 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:95 [inline]
 __se_sys_mmap arch/x86/kernel/sys_x86_64.c:86 [inline]
 __x64_sys_mmap+0xfa/0x110 arch/x86/kernel/sys_x86_64.c:86
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

Memory state around the buggy address:
 ffff88812776df00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88812776df80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88812776e000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff88812776e080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88812776e100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================

Crashes (43):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/07/09 15:49 android13-5.10-lts 50b3a256e550 a0c310a3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (clean fs)] ci2-android-5-10 KASAN: use-after-free Read in ext4_get_inode_usage
2026/05/17 08:34 android13-5.10-lts 1b32327554da de5aae85 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro #1 (corrupt fs)] [mounted in repro #2 (corrupt fs)] ci2-android-5-10 KASAN: use-after-free Read in ext4_get_inode_usage
2026/05/17 01:08 android13-5.10-lts 1b32327554da de5aae85 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro #1 (corrupt fs)] [mounted in repro #2 (corrupt fs)] ci2-android-5-10 KASAN: use-after-free Read in ext4_get_inode_usage
2026/05/17 00:39 android13-5.10-lts 1b32327554da de5aae85 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro #1 (corrupt fs)] [mounted in repro #2 (corrupt fs)] ci2-android-5-10 KASAN: use-after-free Read in ext4_get_inode_usage
2026/05/15 19:16 android13-5.10-lts 1b32327554da 9cd3beaa .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro #1 (corrupt fs)] [mounted in repro #2 (corrupt fs)] ci2-android-5-10 KASAN: use-after-free Read in ext4_get_inode_usage
2026/05/15 18:56 android13-5.10-lts 1b32327554da 9cd3beaa .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro #1 (corrupt fs)] [mounted in repro #2 (corrupt fs)] ci2-android-5-10 KASAN: use-after-free Read in ext4_get_inode_usage
2026/05/15 18:35 android13-5.10-lts 1b32327554da 9cd3beaa .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro #1 (corrupt fs)] [mounted in repro #2 (corrupt fs)] ci2-android-5-10 KASAN: use-after-free Read in ext4_get_inode_usage
2026/05/18 08:05 android13-5.10-lts 1b32327554da de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in ext4_get_inode_usage
2026/05/18 08:00 android13-5.10-lts 1b32327554da de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in ext4_get_inode_usage
2026/05/18 07:10 android13-5.10-lts 1b32327554da de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in ext4_get_inode_usage
2026/05/18 07:10 android13-5.10-lts 1b32327554da de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in ext4_get_inode_usage
2026/05/18 06:05 android13-5.10-lts 1b32327554da de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in ext4_get_inode_usage
2026/05/18 04:30 android13-5.10-lts 1b32327554da de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in ext4_get_inode_usage
2026/05/18 03:22 android13-5.10-lts 1b32327554da de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in ext4_get_inode_usage
2026/05/18 02:52 android13-5.10-lts 1b32327554da de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in ext4_get_inode_usage
2026/05/18 01:59 android13-5.10-lts 1b32327554da de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in ext4_get_inode_usage
2026/05/18 00:34 android13-5.10-lts 1b32327554da de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in ext4_get_inode_usage
2026/05/17 22:10 android13-5.10-lts 1b32327554da de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in ext4_get_inode_usage
2026/05/17 17:46 android13-5.10-lts 1b32327554da de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in ext4_get_inode_usage
2026/05/17 17:29 android13-5.10-lts 1b32327554da de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in ext4_get_inode_usage
2026/05/17 17:17 android13-5.10-lts 1b32327554da de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in ext4_get_inode_usage
2026/05/17 17:00 android13-5.10-lts 1b32327554da de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in ext4_get_inode_usage
2026/05/17 14:34 android13-5.10-lts 1b32327554da de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in ext4_get_inode_usage
2026/05/17 14:17 android13-5.10-lts 1b32327554da de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in ext4_get_inode_usage
2026/05/17 13:46 android13-5.10-lts 1b32327554da de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in ext4_get_inode_usage
2026/05/17 13:46 android13-5.10-lts 1b32327554da de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in ext4_get_inode_usage
2026/05/17 11:02 android13-5.10-lts 1b32327554da de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in ext4_get_inode_usage
2026/05/17 08:05 android13-5.10-lts 1b32327554da de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in ext4_get_inode_usage
2026/05/17 07:03 android13-5.10-lts 1b32327554da de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in ext4_get_inode_usage
2026/05/17 05:57 android13-5.10-lts 1b32327554da de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in ext4_get_inode_usage
2026/05/17 03:31 android13-5.10-lts 1b32327554da de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in ext4_get_inode_usage
2026/05/17 02:10 android13-5.10-lts 1b32327554da de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in ext4_get_inode_usage
2026/05/17 01:59 android13-5.10-lts 1b32327554da de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in ext4_get_inode_usage
2026/05/17 00:36 android13-5.10-lts 1b32327554da de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in ext4_get_inode_usage
2026/05/15 18:08 android13-5.10-lts 1b32327554da 9cd3beaa .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in ext4_get_inode_usage
2026/05/15 18:07 android13-5.10-lts 1b32327554da 9cd3beaa .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in ext4_get_inode_usage
2026/05/18 06:35 android13-5.10-lts 1b32327554da de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in ext4_get_inode_usage
2026/05/17 22:06 android13-5.10-lts 1b32327554da de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in ext4_get_inode_usage
2026/05/17 15:20 android13-5.10-lts 1b32327554da de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in ext4_get_inode_usage
2026/05/17 13:33 android13-5.10-lts 1b32327554da de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in ext4_get_inode_usage
2026/05/17 03:41 android13-5.10-lts 1b32327554da de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in ext4_get_inode_usage
2026/05/16 21:57 android13-5.10-lts 1b32327554da de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Read in ext4_get_inode_usage
* Struck through repros no longer work on HEAD.