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KASAN: use-after-free Read in hpfs_get_ea

Status: upstream: reported C repro on 2025/07/26 19:47
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+1ded3afdecabdd33273d@syzkaller.appspotmail.com
First crash: 269d, last: 11h01m
▶ ▼ Bug presence (1)
Date Name Commit Repro Result
2025/11/06 upstream (ToT) dc77806cf3b4 C [report] KASAN: use-after-free Read in hpfs_get_ea
▶ ▼ Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: use-after-free Read in hpfs_get_ea fs 19 C error 7681 8m 278d 0/29 upstream: reported C repro on 2025/07/17 19:14
linux-6.6 KASAN: use-after-free Read in hpfs_get_ea origin:upstream 19 C error 364 2d20h 269d 0/2 upstream: reported C repro on 2025/07/27 17:30
linux-6.1 KASAN: use-after-free Read in hpfs_get_ea origin:upstream 19 C 961 10h03m 269d 0/3 upstream: reported C repro on 2025/07/27 17:28
▶ ▼ Last patch testing requests (2)
Created Duration User Patch Repo Result
2025/08/12 00:12 13m retest repro linux-5.15.y report log
2025/08/12 00:12 12m retest repro linux-5.15.y report log

Sample crash report:
hpfs: filesystem error: warning: spare dnodes used, try chkdsk
hpfs: You really don't want any checks? You are crazy...
hpfs: hpfs_map_sector(): read error
hpfs: code page support is disabled
==================================================================
BUG: KASAN: use-after-free in strcmp+0x67/0xb0 lib/string.c:400
Read of size 1 at addr ffff8880606d18a6 by task syz.0.18/4342

CPU: 1 PID: 4342 Comm: syz.0.18 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 print_address_description+0x60/0x2d0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0xdf/0x130 mm/kasan/report.c:451
 strcmp+0x67/0xb0 lib/string.c:400
 hpfs_get_ea+0x132/0xdd0 fs/hpfs/ea.c:139
 hpfs_read_inode+0x1a3/0x1050 fs/hpfs/inode.c:63
 hpfs_fill_super+0x135a/0x1fd0 fs/hpfs/super.c:712
 mount_bdev+0x287/0x3c0 fs/super.c:1400
 legacy_get_tree+0xe6/0x180 fs/fs_context.c:611
 vfs_get_tree+0x88/0x270 fs/super.c:1530
 do_new_mount+0x24a/0xa40 fs/namespace.c:3034
 do_mount fs/namespace.c:3377 [inline]
 __do_sys_mount fs/namespace.c:3585 [inline]
 __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3562
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fab682ef20a
Code: 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd14807f48 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffd14807fd0 RCX: 00007fab682ef20a
RDX: 000020000000a000 RSI: 0000200000009ec0 RDI: 00007ffd14807f90
RBP: 000020000000a000 R08: 00007ffd14807fd0 R09: 0000000003210041
R10: 0000000003210041 R11: 0000000000000246 R12: 0000200000009ec0
R13: 00007ffd14807f90 R14: 0000000000009e15 R15: 00002000000002c0
 </TASK>

The buggy address belongs to the page:
page:ffffea000181b440 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x606d1
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffffea000181b488 ffffea000181b408 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 0x1100dca(GFP_HIGHUSER_MOVABLE|__GFP_ZERO), pid 4187, ts 59885914484, free_ts 60021647851
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x1bbd/0x1ca0 mm/page_alloc.c:4192
 __alloc_pages+0x1ee/0x480 mm/page_alloc.c:5487
 alloc_pages_vma+0x393/0x7c0 mm/mempolicy.c:2146
 do_anonymous_page mm/memory.c:3838 [inline]
 handle_pte_fault mm/memory.c:4648 [inline]
 __handle_mm_fault mm/memory.c:4785 [inline]
 handle_mm_fault+0x23be/0x4410 mm/memory.c:4883
 do_user_addr_fault+0x489/0xc80 arch/x86/mm/fault.c:1355
 handle_page_fault arch/x86/mm/fault.c:1443 [inline]
 exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1496
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1340 [inline]
 free_pcp_prepare mm/page_alloc.c:1391 [inline]
 free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317
 free_unref_page_list+0x119/0x820 mm/page_alloc.c:3433
 release_pages+0x186c/0x1be0 mm/swap.c:963
 tlb_batch_pages_flush mm/mmu_gather.c:49 [inline]
 tlb_flush_mmu_free mm/mmu_gather.c:240 [inline]
 tlb_flush_mmu mm/mmu_gather.c:247 [inline]
 tlb_finish_mmu+0x176/0x300 mm/mmu_gather.c:338
 unmap_region+0x344/0x3b0 mm/mmap.c:2669
 __do_munmap+0x9f8/0xdf0 mm/mmap.c:2899
 __vm_munmap+0x140/0x240 mm/mmap.c:2952
 __do_sys_munmap mm/mmap.c:2978 [inline]
 __se_sys_munmap mm/mmap.c:2974 [inline]
 __x64_sys_munmap+0x67/0x70 mm/mmap.c:2974
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

Memory state around the buggy address:
 ffff8880606d1780: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8880606d1800: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff8880606d1880: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                               ^
 ffff8880606d1900: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8880606d1980: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================

Crashes (507):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/02/14 21:40 linux-5.15.y e45d5d41c134 1e62d198 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan KASAN: use-after-free Read in hpfs_get_ea
2025/11/04 12:48 linux-5.15.y cc5ec8769306 686bf657 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan KASAN: use-after-free Read in hpfs_get_ea
2025/07/26 20:44 linux-5.15.y c79648372d02 fb8f743d .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Read in hpfs_get_ea
2025/07/26 20:02 linux-5.15.y c79648372d02 fb8f743d .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Read in hpfs_get_ea
2026/04/22 07:22 linux-5.15.y b9d57c40a767 0b6ab7ec .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in hpfs_get_ea
2026/04/21 22:17 linux-5.15.y b9d57c40a767 0b6ab7ec .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in hpfs_get_ea
2026/04/20 21:46 linux-5.15.y b9d57c40a767 e65da4ee .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in hpfs_get_ea
2026/04/20 14:03 linux-5.15.y b9d57c40a767 e65da4ee .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in hpfs_get_ea
2026/04/19 10:16 linux-5.15.y b9d57c40a767 303e2802 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in hpfs_get_ea
2026/04/18 21:24 linux-5.15.y b9d57c40a767 303e2802 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in hpfs_get_ea
2026/04/16 19:21 linux-5.15.y 91d48252ad4b 4743f87d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in hpfs_get_ea
2026/04/12 07:40 linux-5.15.y 91d48252ad4b 38c8e246 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in hpfs_get_ea
2026/04/11 20:08 linux-5.15.y 91d48252ad4b 38c8e246 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in hpfs_get_ea
2026/04/11 14:18 linux-5.15.y 91d48252ad4b 38c8e246 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in hpfs_get_ea
2026/04/10 14:26 linux-5.15.y 91d48252ad4b 38c8e246 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in hpfs_get_ea
2026/04/10 13:03 linux-5.15.y 91d48252ad4b 38c8e246 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in hpfs_get_ea
2026/04/06 09:22 linux-5.15.y 91d48252ad4b 4440e7c2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in hpfs_get_ea
2026/04/06 03:15 linux-5.15.y 91d48252ad4b 4440e7c2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in hpfs_get_ea
2026/04/04 07:45 linux-5.15.y 91d48252ad4b 4440e7c2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in hpfs_get_ea
2026/03/30 12:42 linux-5.15.y 91d48252ad4b dcaebc52 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in hpfs_get_ea
2026/03/30 08:16 linux-5.15.y 91d48252ad4b dcaebc52 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in hpfs_get_ea
2026/03/29 20:06 linux-5.15.y 91d48252ad4b b5ceaad2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in hpfs_get_ea
2026/03/29 16:20 linux-5.15.y 91d48252ad4b b5ceaad2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in hpfs_get_ea
2026/03/23 11:48 linux-5.15.y 91d48252ad4b 4933dba2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in hpfs_get_ea
2026/03/23 09:17 linux-5.15.y 91d48252ad4b 5b92003d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in hpfs_get_ea
2026/03/10 01:27 linux-5.15.y 91d48252ad4b 6972f302 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in hpfs_get_ea
2026/03/09 18:16 linux-5.15.y 91d48252ad4b 176bead5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in hpfs_get_ea
2026/03/09 04:42 linux-5.15.y 91d48252ad4b 5cb44a80 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in hpfs_get_ea
2026/03/05 12:08 linux-5.15.y 91d48252ad4b d20b04c8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in hpfs_get_ea
2026/03/05 09:51 linux-5.15.y 91d48252ad4b a9fe5c9e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in hpfs_get_ea
2026/03/04 20:09 linux-5.15.y 91d48252ad4b e6b6b96b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in hpfs_get_ea
2026/03/04 10:07 linux-5.15.y 3330a8d33e08 4180d919 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in hpfs_get_ea
2026/03/04 07:44 linux-5.15.y 3330a8d33e08 4180d919 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in hpfs_get_ea
2026/03/01 04:35 linux-5.15.y 3330a8d33e08 43249bac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in hpfs_get_ea
2026/02/26 18:15 linux-5.15.y 3330a8d33e08 ffa54287 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in hpfs_get_ea
2026/02/22 22:49 linux-5.15.y 3330a8d33e08 6e7b5511 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in hpfs_get_ea
2026/02/22 00:24 linux-5.15.y 3330a8d33e08 6e7b5511 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in hpfs_get_ea
2026/02/16 02:39 linux-5.15.y e45d5d41c134 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in hpfs_get_ea
2026/02/16 02:39 linux-5.15.y e45d5d41c134 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in hpfs_get_ea
2026/02/15 21:06 linux-5.15.y e45d5d41c134 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in hpfs_get_ea
2026/02/14 21:04 linux-5.15.y e45d5d41c134 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in hpfs_get_ea
2026/02/10 05:52 linux-5.15.y 7b232985052f 4ab09a02 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in hpfs_get_ea
2026/02/06 03:01 linux-5.15.y 9eec9a14ee10 f03c4191 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in hpfs_get_ea
2026/02/05 21:40 linux-5.15.y 9eec9a14ee10 f03c4191 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in hpfs_get_ea
2026/01/23 04:53 linux-5.15.y 9eec9a14ee10 82c9c083 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in hpfs_get_ea
2026/01/23 01:48 linux-5.15.y 9eec9a14ee10 82c9c083 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in hpfs_get_ea
2026/01/20 23:03 linux-5.15.y 9eec9a14ee10 06648d9c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in hpfs_get_ea
2026/01/16 23:10 linux-5.15.y 68efe5a6c16a 20d37d28 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in hpfs_get_ea
2026/01/16 23:08 linux-5.15.y 68efe5a6c16a 20d37d28 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in hpfs_get_ea
2025/07/28 09:09 linux-5.15.y c79648372d02 fb8f743d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Read in hpfs_get_ea
2025/07/26 19:46 linux-5.15.y c79648372d02 fb8f743d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Read in hpfs_get_ea
2026/04/15 08:34 linux-5.15.y 91d48252ad4b e2e976a8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in hpfs_get_ea
* Struck through repros no longer work on HEAD.