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KASAN: slab-out-of-bounds Write in udf_write_aext

Status: upstream: reported C repro on 2022/09/25 01:59
Reported-by: syzbot+56e4d8da000b89003187@syzkaller.appspotmail.com
First crash: 137d, last: 6d00h
similar bugs (2):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: slab-out-of-bounds Write in udf_write_aext udf tmpfs erofs C error 562 5h37m 135d 0/24 upstream: reported C repro on 2022/09/26 17:49
linux-4.19 KASAN: slab-out-of-bounds Write in udf_write_aext udf tmpfs erofs C error 56 4d06h 465d 0/1 upstream: reported C repro on 2021/10/31 06:20

Sample crash report:
UDF-fs: Scanning with blocksize 1024 failed
UDF-fs: warning (device loop0): udf_load_vrs: No VRS found
UDF-fs: Scanning with blocksize 2048 failed
UDF-fs: INFO Mounting volume 'LinuxUDF', timestamp 2022/11/22 14:59 (1000)
==================================================================
BUG: KASAN: slab-out-of-bounds in udf_write_aext+0x6e3/0x7d0 fs/udf/inode.c:2076
Write of size 4 at addr ffff88809626e130 by task syz-executor409/7967

CPU: 0 PID: 7967 Comm: syz-executor409 Not tainted 4.14.302-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x1b2/0x281 lib/dump_stack.c:58
 print_address_description.cold+0x54/0x1d3 mm/kasan/report.c:252
 kasan_report_error.cold+0x8a/0x191 mm/kasan/report.c:351
 kasan_report mm/kasan/report.c:409 [inline]
 __asan_report_store_n_noabort+0x6b/0x80 mm/kasan/report.c:446
 udf_write_aext+0x6e3/0x7d0 fs/udf/inode.c:2076
 udf_add_entry+0xc54/0x2710 fs/udf/namei.c:501
 udf_mkdir+0x122/0x620 fs/udf/namei.c:699
 vfs_mkdir+0x463/0x6e0 fs/namei.c:3851
 SYSC_mkdirat fs/namei.c:3874 [inline]
 SyS_mkdirat+0x1fd/0x270 fs/namei.c:3858
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x5e/0xd3
RIP: 0033:0x7f5e088eede7
RSP: 002b:00007ffce02dc308 EFLAGS: 00000286 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 00005555565332c0 RCX: 00007f5e088eede7
RDX: 0000000000046000 RSI: 00000000000001ff RDI: 0000000020000300
RBP: 00000000ffffffff R08: 0000000000000000 R09: 0000000000000000
R10: 00007ffce02dc3a0 R11: 0000000000000286 R12: 0000000020000300
R13: 0000000000000000 R14: 0000000000000000 R15: 00007ffce02dc3a0

Allocated by task 7967:
 save_stack mm/kasan/kasan.c:447 [inline]
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:551
 __do_kmalloc mm/slab.c:3720 [inline]
 __kmalloc+0x15a/0x400 mm/slab.c:3729
 kmalloc include/linux/slab.h:493 [inline]
 kzalloc include/linux/slab.h:661 [inline]
 udf_new_inode+0x98d/0xce0 fs/udf/ialloc.c:70
 udf_mkdir+0x95/0x620 fs/udf/namei.c:692
 vfs_mkdir+0x463/0x6e0 fs/namei.c:3851
 SYSC_mkdirat fs/namei.c:3874 [inline]
 SyS_mkdirat+0x1fd/0x270 fs/namei.c:3858
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x5e/0xd3

Freed by task 0:
(stack is not available)

The buggy address belongs to the object at ffff88809626e140
 which belongs to the cache kmalloc-4096 of size 4096
The buggy address is located 16 bytes to the left of
 4096-byte region [ffff88809626e140, ffff88809626f140)
The buggy address belongs to the page:
page:ffffea0002589b80 count:1 mapcount:0 mapping:ffff88809626e140 index:0x0 compound_mapcount: 0
flags: 0xfff00000008100(slab|head)
raw: 00fff00000008100 ffff88809626e140 0000000000000000 0000000100000001
raw: ffffea0002ccde20 ffffea0002ccb1a0 ffff88813fe74dc0 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88809626e000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88809626e080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88809626e100: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
                                     ^
 ffff88809626e180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88809626e200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================

Fix bisection attempts:
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets Title
ci2-linux-4-14 2023/02/03 05:53 linux-4.14.y 3949d1610004 ab32d508 .config console log report syz C
ci2-linux-4-14 2022/10/28 17:11 linux-4.14.y 41f36d7859a7 0042f2b4 .config console log report syz C
* Struck through repros no longer work on HEAD.
Crashes (15):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets Title
ci2-linux-4-14 2023/01/03 01:37 linux-4.14.y c4215ee4771b ab32d508 .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] KASAN: slab-out-of-bounds Write in udf_write_aext
ci2-linux-4-14 2023/01/02 17:53 linux-4.14.y c4215ee4771b ab32d508 .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] KASAN: slab-out-of-bounds Write in udf_write_aext
ci2-linux-4-14 2022/12/30 18:09 linux-4.14.y c4215ee4771b 44712fbc .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] KASAN: slab-out-of-bounds Write in udf_write_aext
ci2-linux-4-14 2022/12/30 06:21 linux-4.14.y c4215ee4771b 44712fbc .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] KASAN: slab-out-of-bounds Write in udf_write_aext
ci2-linux-4-14 2022/12/30 04:15 linux-4.14.y c4215ee4771b 44712fbc .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] KASAN: slab-out-of-bounds Write in udf_write_aext
ci2-linux-4-14 2022/12/29 22:35 linux-4.14.y c4215ee4771b 44712fbc .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] KASAN: slab-out-of-bounds Write in udf_write_aext
ci2-linux-4-14 2022/12/26 20:47 linux-4.14.y c4215ee4771b 9da18ae8 .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] KASAN: slab-out-of-bounds Write in udf_write_aext
ci2-linux-4-14 2022/12/19 10:53 linux-4.14.y c4215ee4771b 05494336 .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] KASAN: slab-out-of-bounds Write in udf_write_aext
ci2-linux-4-14 2022/09/25 01:58 linux-4.14.y 4edbf74132a4 0042f2b4 .config console log report syz C [disk image] [vmlinux] KASAN: slab-out-of-bounds Write in udf_write_aext
ci2-linux-4-14 2022/12/28 02:56 linux-4.14.y c4215ee4771b 44712fbc .config console log report info [disk image] [vmlinux] [kernel image] KASAN: slab-out-of-bounds Write in udf_write_aext
ci2-linux-4-14 2022/12/25 22:32 linux-4.14.y c4215ee4771b 9da18ae8 .config console log report info [disk image] [vmlinux] [kernel image] KASAN: slab-out-of-bounds Write in udf_write_aext
ci2-linux-4-14 2022/12/25 22:32 linux-4.14.y c4215ee4771b 9da18ae8 .config console log report info [disk image] [vmlinux] [kernel image] KASAN: slab-out-of-bounds Write in udf_write_aext
ci2-linux-4-14 2022/12/19 07:58 linux-4.14.y c4215ee4771b 05494336 .config console log report info [disk image] [vmlinux] [kernel image] KASAN: slab-out-of-bounds Write in udf_write_aext
ci2-linux-4-14 2022/12/16 00:02 linux-4.14.y c4215ee4771b 6f9c033e .config console log report info [disk image] [vmlinux] [kernel image] KASAN: slab-out-of-bounds Write in udf_write_aext
ci2-linux-4-14 2022/12/09 22:37 linux-4.14.y 65afe34ac33d 67be1ae7 .config console log report info [disk image] [vmlinux] [kernel image] KASAN: slab-out-of-bounds Write in udf_write_aext
* Struck through repros no longer work on HEAD.