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KASAN: use-after-free Read in get_max_inline_xattr_value_size

Status: auto-obsoleted due to no activity on 2024/01/19 14:48
Bug presence: origin:lts
[Documentation on labels]
Reported-by: syzbot+4307d88364336839639e@syzkaller.appspotmail.com
First crash: 317d, last: 228d
Cause bisection: failed (error log, bisect log)
  
Fix bisection: fixed by (bisect log) :
commit 1d2caddbeeee56fbbc36b428c5b909c3ad88eb7f
Author: Theodore Ts'o <tytso@mit.edu>
Date: Fri May 12 19:11:02 2023 +0000

  ext4: add bounds checking in get_max_inline_xattr_value_size()

  
Bug presence (2)
Date Name Commit Repro Result
2023/07/15 lts (merge base) b1644a0031cf C [report] KASAN: use-after-free Read in get_max_inline_xattr_value_size
2023/07/15 upstream (ToT) b6e6cc1f78c7 C Didn't crash
Similar bugs (6)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-5-10 KASAN: slab-out-of-bounds Read in get_max_inline_xattr_value_size ext4 C error 4 427d 507d 2/2 fixed on 2023/06/07 17:22
upstream KASAN: slab-out-of-bounds Read in get_max_inline_xattr_value_size ext4 C 21 386d 424d 22/26 fixed on 2023/07/01 16:05
android-54 KASAN: use-after-free Read in get_max_inline_xattr_value_size ext4 C 20 428d 507d 2/2 fixed on 2023/06/07 17:22
android-54 KASAN: use-after-free Read in get_max_inline_xattr_value_size (2) C 3 309d 317d 0/2 auto-obsoleted due to no activity on 2023/10/31 04:10
android-5-15 KASAN: use-after-free Read in get_max_inline_xattr_value_size ext4 C error 4 427d 507d 2/2 fixed on 2023/06/07 17:22
linux-4.19 KASAN: slab-out-of-bounds Read in get_max_inline_xattr_value_size ext4 C error 1 486d 486d 0/1 upstream: reported C repro on 2023/01/27 02:26
Last patch testing requests (2)
Created Duration User Patch Repo Result
2023/11/06 14:42 14m retest repro android14-6.1 OK log
2023/08/28 14:12 14m retest repro android14-6.1 report log

Sample crash report:
loop0: detected capacity change from 0 to 2048
EXT4-fs (loop0): mounted filesystem without journal. Quota mode: none.
EXT4-fs error (device loop0): ext4_xattr_ibody_get:619: inode #18: comm syz-executor289: corrupted in-inode xattr
==================================================================
BUG: KASAN: use-after-free in get_max_inline_xattr_value_size+0x36e/0x510 fs/ext4/inline.c:62
Read of size 4 at addr ffff888121308004 by task syz-executor289/312

CPU: 1 PID: 312 Comm: syz-executor289 Not tainted 6.1.25-syzkaller-00027-ga24911abfd55 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/03/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x151/0x1b7 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:316 [inline]
 print_report+0x158/0x4e0 mm/kasan/report.c:427
 kasan_report+0x13c/0x170 mm/kasan/report.c:531
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:350
 get_max_inline_xattr_value_size+0x36e/0x510 fs/ext4/inline.c:62
 ext4_get_max_inline_size+0x13d/0x1f0 fs/ext4/inline.c:113
 ext4_try_to_write_inline_data+0xd3/0x1420 fs/ext4/inline.c:663
 ext4_write_begin+0x200/0xfb0 fs/ext4/inode.c:1179
 ext4_da_write_begin+0x2ff/0x920 fs/ext4/inode.c:2987
 generic_perform_write+0x2f9/0x5c0 mm/filemap.c:3765
 ext4_buffered_write_iter+0x360/0x640 fs/ext4/file.c:285
 ext4_file_write_iter+0x194/0x1cf0
 call_write_iter include/linux/fs.h:2215 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x8d1/0xe80 fs/read_write.c:584
 ksys_write+0x199/0x2c0 fs/read_write.c:637
 __do_sys_write fs/read_write.c:649 [inline]
 __se_sys_write fs/read_write.c:646 [inline]
 __x64_sys_write+0x7b/0x90 fs/read_write.c:646
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fc74bc54329
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 21 18 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:00007ffdb248cf38 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc74bc54329
RDX: 0000000000000001 RSI: 0000000020000280 RDI: 0000000000000004
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 431bde82d7b634db R15: 00007ffdb248cfa0
 </TASK>

The buggy address belongs to the physical page:
page:ffffea000484c200 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x121308
flags: 0x4000000000000000(zone=1)
raw: 4000000000000000 ffffea000484c248 ffffea000484c948 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 0x140cca(GFP_HIGHUSER_MOVABLE|__GFP_COMP), pid 306, tgid 306 (syz-executor289), ts 24774942178, free_ts 24859714760
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x213/0x220 mm/page_alloc.c:2581
 prep_new_page mm/page_alloc.c:2588 [inline]
 get_page_from_freelist+0x276c/0x2850 mm/page_alloc.c:4385
 __alloc_pages+0x3a1/0x780 mm/page_alloc.c:5662
 __folio_alloc+0x15/0x40 mm/page_alloc.c:5694
 __folio_alloc_node include/linux/gfp.h:245 [inline]
 folio_alloc include/linux/gfp.h:274 [inline]
 shmem_alloc_folio mm/shmem.c:1578 [inline]
 shmem_alloc_and_acct_folio+0x78c/0xa50 mm/shmem.c:1603
 shmem_get_folio_gfp+0x12d4/0x24b0 mm/shmem.c:1931
 shmem_get_folio mm/shmem.c:2062 [inline]
 shmem_write_begin+0x164/0x3a0 mm/shmem.c:2550
 generic_perform_write+0x2f9/0x5c0 mm/filemap.c:3765
 __generic_file_write_iter+0x174/0x3a0 mm/filemap.c:3893
 generic_file_write_iter+0xb1/0x310 mm/filemap.c:3925
 call_write_iter include/linux/fs.h:2215 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x8d1/0xe80 fs/read_write.c:584
 ksys_write+0x199/0x2c0 fs/read_write.c:637
 __do_sys_write fs/read_write.c:649 [inline]
 __se_sys_write fs/read_write.c:646 [inline]
 __x64_sys_write+0x7b/0x90 fs/read_write.c:646
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:26 [inline]
 free_pages_prepare mm/page_alloc.c:1493 [inline]
 free_pcp_prepare mm/page_alloc.c:1567 [inline]
 free_unref_page_prepare+0x83d/0x850 mm/page_alloc.c:3484
 free_unref_page_list+0xf6/0x6c0 mm/page_alloc.c:3626
 release_pages+0xf7f/0xfe0 mm/swap.c:1055
 __pagevec_release+0x84/0x100 mm/swap.c:1075
 pagevec_release include/linux/pagevec.h:71 [inline]
 folio_batch_release include/linux/pagevec.h:135 [inline]
 shmem_undo_range+0x609/0x15b0 mm/shmem.c:949
 shmem_truncate_range mm/shmem.c:1048 [inline]
 shmem_evict_inode+0x25f/0xa30 mm/shmem.c:1157
 evict+0x2a3/0x630 fs/inode.c:664
 iput_final fs/inode.c:1747 [inline]
 iput+0x642/0x870 fs/inode.c:1773
 dentry_unlink_inode+0x34f/0x440 fs/dcache.c:401
 __dentry_kill+0x447/0x650 fs/dcache.c:607
 dentry_kill+0xc0/0x2a0
 dput+0x160/0x310 fs/dcache.c:913
 __fput+0x5f0/0x870 fs/file_table.c:328
 ____fput+0x15/0x20 fs/file_table.c:348
 task_work_run+0x24d/0x2e0 kernel/task_work.c:179
 ptrace_notify+0x29e/0x350 kernel/signal.c:2357

Memory state around the buggy address:
 ffff888121307f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888121307f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888121308000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff888121308080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888121308100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
EXT4-fs error (device loop0): ext4_read_block_bitmap_nowait:438: comm syz-executor289: Invalid block bitmap block 4294967295 in block_group 0

Crashes (10):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/07/15 09:20 android14-6.1 a24911abfd55 35d9ecc5 .config strace log report syz C [mounted in repro] ci2-android-6-1 KASAN: use-after-free Read in get_max_inline_xattr_value_size
2023/10/11 14:48 android14-6.1 83ebd502359f 83165b57 .config console log report info ci2-android-6-1 KASAN: use-after-free Read in get_max_inline_xattr_value_size
2023/10/09 00:39 android14-6.1 1fe248991f96 5e837c76 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-1 KASAN: use-after-free Read in get_max_inline_xattr_value_size
2023/09/24 15:44 android14-6.1 060ebb378d1c 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-1 KASAN: use-after-free Read in get_max_inline_xattr_value_size
2023/07/17 14:13 android14-6.1 f6707f352b54 20f8b3c2 .config console log report info ci2-android-6-1 KASAN: use-after-free Read in get_max_inline_xattr_value_size
2023/07/17 05:21 android14-6.1 f6707f352b54 35d9ecc5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-1 KASAN: use-after-free Read in get_max_inline_xattr_value_size
2023/07/16 16:49 android14-6.1 f6707f352b54 35d9ecc5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-1 KASAN: use-after-free Read in get_max_inline_xattr_value_size
2023/07/15 14:56 android14-6.1 f6707f352b54 35d9ecc5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-1 KASAN: use-after-free Read in get_max_inline_xattr_value_size
2023/07/15 11:08 android14-6.1 f6707f352b54 35d9ecc5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-1 KASAN: use-after-free Read in get_max_inline_xattr_value_size
2023/07/15 09:04 android14-6.1 a24911abfd55 35d9ecc5 .config console log report info ci2-android-6-1 KASAN: use-after-free Read in get_max_inline_xattr_value_size
* Struck through repros no longer work on HEAD.