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KASAN: use-after-free Read in ext4_search_dir

Status: upstream: reported C repro on 2023/05/11 14:29
Subsystems: ext4
Labels: prio:low
[Documentation on labels]
Reported-by: syzbot+34a0f26f0f61c4888ea4@syzkaller.appspotmail.com
First crash: 217d, last: 4d12h
Cause bisection: failed (error log, bisect log)
  
▶ ▼ Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [ext4?] KASAN: use-after-free Read in ext4_search_dir 1 (3) 2023/05/22 12:57
▶ ▼ Similar bugs (5)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 KASAN: use-after-free Read in ext4_search_dir origin:upstream C 1 9d13h 177d 0/3 upstream: reported C repro on 2023/06/16 15:52
android-6-1 KASAN: use-after-free Read in ext4_search_dir origin:upstream C error 2 9d20h 49d 0/2 upstream: reported C repro on 2023/10/22 16:55
linux-6.1 KASAN: use-after-free Read in ext4_search_dir origin:upstream C 1 9d04h 175d 0/3 upstream: reported C repro on 2023/06/18 19:29
android-5-15 KASAN: slab-out-of-bounds Read in ext4_search_dir origin:upstream C 1 9d20h 23d 0/2 upstream: reported C repro on 2023/11/17 09:38
android-5-10 KASAN: slab-out-of-bounds Read in ext4_search_dir C 1 9d20h 23d 0/2 upstream: reported C repro on 2023/11/17 09:38
▶ ▼ Last patch testing requests (5)
Created Duration User Patch Repo Result
2023/12/06 17:45 15m retest repro upstream report log
2023/12/06 17:56 13m retest repro upstream report log
2023/12/06 17:45 10m retest repro upstream report log
2023/10/26 03:25 16m retest repro linux-next report log
2023/09/12 05:35 14m retest repro upstream report log
▶ ▼ Fix bisection attempts (2)
Created Duration User Patch Repo Result
2023/07/28 08:18 1h22m bisect fix upstream job log (0) log
2023/06/16 08:13 38m bisect fix upstream job log (0) log

Sample crash report:
==================================================================
BUG: KASAN: use-after-free in ext4_search_dir+0xf2/0x1b0 fs/ext4/namei.c:1543
Read of size 1 at addr ffff88806bcc4d23 by task syz-executor342/5059

CPU: 1 PID: 5059 Comm: syz-executor342 Not tainted 6.7.0-rc1-syzkaller-00125-g7475e51b8796 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:364 [inline]
 print_report+0x163/0x540 mm/kasan/report.c:475
 kasan_report+0x142/0x170 mm/kasan/report.c:588
 ext4_search_dir+0xf2/0x1b0 fs/ext4/namei.c:1543
 ext4_find_inline_entry+0x4ba/0x5e0 fs/ext4/inline.c:1694
 __ext4_find_entry+0x2b4/0x1b30 fs/ext4/namei.c:1616
 ext4_lookup_entry fs/ext4/namei.c:1771 [inline]
 ext4_lookup+0x17a/0x750 fs/ext4/namei.c:1839
 lookup_one_qstr_excl+0x11b/0x250 fs/namei.c:1609
 filename_create+0x297/0x530 fs/namei.c:3876
 do_mkdirat+0xbd/0x3a0 fs/namei.c:4121
 __do_sys_mkdirat fs/namei.c:4144 [inline]
 __se_sys_mkdirat fs/namei.c:4142 [inline]
 __x64_sys_mkdirat+0x89/0xa0 fs/namei.c:4142
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x45/0x110 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x63/0x6b
RIP: 0033:0x7f8c74d293a9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 21 1f 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffec3db0d18 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f8c74d6d1d7 RCX: 00007f8c74d293a9
RDX: 0000000000000000 RSI: 0000000020000040 RDI: 00000000ffffff9c
RBP: 0030656c69662f2e R08: 00000000000014ef R09: 0000000020001580
R10: 00000000000014f3 R11: 0000000000000246 R12: 0000000000000031
R13: 0000000000000003 R14: 00007f8c74da06c0 R15: 00007ffec3db0dfa
 </TASK>

The buggy address belongs to the physical page:
page:ffffea0001af3100 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x6bcc4
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000000 dead000000000100 dead000000000122 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 0x8(__GFP_MOVABLE), pid 1, tgid 1 (swapper/0), ts 14724262823, free_ts 16180710530
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x1e6/0x210 mm/page_alloc.c:1537
 split_map_pages+0x24a/0x510 mm/compaction.c:97
 isolate_freepages_range+0x476/0x4d0 mm/compaction.c:774
 alloc_contig_range+0x62e/0x9a0 mm/page_alloc.c:6411
 __alloc_contig_pages mm/page_alloc.c:6434 [inline]
 alloc_contig_pages+0x3f4/0x4f0 mm/page_alloc.c:6514
 debug_vm_pgtable_alloc_huge_page+0xb9/0x110 mm/debug_vm_pgtable.c:1095
 init_args+0x837/0xb10 mm/debug_vm_pgtable.c:1277
 debug_vm_pgtable+0xe0/0x540 mm/debug_vm_pgtable.c:1315
 do_one_initcall+0x234/0x810 init/main.c:1236
 do_initcall_level+0x157/0x210 init/main.c:1298
 do_initcalls+0x3f/0x80 init/main.c:1314
 kernel_init_freeable+0x429/0x5c0 init/main.c:1551
 kernel_init+0x1d/0x2a0 init/main.c:1441
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1137 [inline]
 free_unref_page_prepare+0x931/0xa60 mm/page_alloc.c:2347
 free_unref_page+0x37/0x3f0 mm/page_alloc.c:2487
 free_contig_range+0x9e/0x160 mm/page_alloc.c:6536
 destroy_args+0x8a/0x890 mm/debug_vm_pgtable.c:1028
 debug_vm_pgtable+0x4ba/0x540 mm/debug_vm_pgtable.c:1408
 do_one_initcall+0x234/0x810 init/main.c:1236
 do_initcall_level+0x157/0x210 init/main.c:1298
 do_initcalls+0x3f/0x80 init/main.c:1314
 kernel_init_freeable+0x429/0x5c0 init/main.c:1551
 kernel_init+0x1d/0x2a0 init/main.c:1441
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242

Memory state around the buggy address:
 ffff88806bcc4c00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88806bcc4c80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88806bcc4d00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                               ^
 ffff88806bcc4d80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88806bcc4e00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================

Crashes (17):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/11/17 08:55 upstream 7475e51b8796 cb976f63 .config strace log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro #1] [mounted in repro #2] ci2-upstream-fs KASAN: use-after-free Read in ext4_search_dir
2023/05/17 08:12 upstream f1fcbaa18b28 11c89444 .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro #1] [mounted in repro #2] ci2-upstream-fs KASAN: use-after-free Read in ext4_search_dir
2023/08/03 00:18 linux-next 626c67169f99 39a91c18 .config strace log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro #1] [mounted in repro #2] ci-upstream-linux-next-kasan-gce-root KASAN: use-after-free Read in ext4_search_dir
2023/06/23 12:45 upstream 8a28a0b6f1a1 09ffe269 .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro #1] [mounted in repro #2] ci-upstream-kasan-gce-root KASAN: slab-out-of-bounds Read in ext4_search_dir
2023/05/17 07:29 upstream f1fcbaa18b28 11c89444 .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro #1] [mounted in repro #2] ci-upstream-kasan-gce-smack-root KASAN: slab-out-of-bounds Read in ext4_search_dir
2023/11/17 08:25 upstream 7475e51b8796 cb976f63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: use-after-free Read in ext4_search_dir
2023/11/03 13:56 upstream 8f6f76a6a29f c4ac074c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: use-after-free Read in ext4_search_dir
2023/10/11 19:40 upstream 1c8b86a3799f 83165b57 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root KASAN: use-after-free Read in ext4_search_dir
2023/09/28 09:24 upstream 633b47cb009d c2ab1e5d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: use-after-free Read in ext4_search_dir
2023/08/29 05:06 upstream 727dbda16b83 7ba13a15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: use-after-free Read in ext4_search_dir
2023/08/19 17:53 upstream aa9ea98cca3a d216d8a0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: use-after-free Read in ext4_search_dir
2023/05/17 07:02 upstream f1fcbaa18b28 11c89444 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root KASAN: use-after-free Read in ext4_search_dir
2023/05/07 07:18 upstream fc4354c6e5c2 90c93c40 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: use-after-free Read in ext4_search_dir
2023/09/16 23:31 linux-next dfa449a58323 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root KASAN: use-after-free Read in ext4_search_dir
2023/11/22 17:40 upstream c2d5304e6c64 03e12510 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: slab-out-of-bounds Read in ext4_search_dir
2023/10/12 02:06 upstream 8182d7a3f1b8 83165b57 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: slab-out-of-bounds Read in ext4_search_dir
2023/09/20 03:40 upstream 2cf0f7156238 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: slab-out-of-bounds Read in ext4_search_dir
* Struck through repros no longer work on HEAD.