Bug 244344

Created attachment 211868 [details]
Contains PoC UFS image and detailed logs includes 13-current, 12.1-release and 12.1-stable

Hi there,

Kernel Panic is observed while attaching the usb drive which contains malicious UFS filesystem image. No user authentication and interaction is needed.

Just flash the attached UFS image to usb drive and plug the usb drive to FreeBSD 13-CURRENT, 12.1-RELEASE, or 12.1-STABLE.


[Kernel Log - FreeBSD 13-CURRENT (UAF)]

freebsd dumped core - see /var/crash/vmcore.2

Fri Feb 21 07:01:11 UTC 2020

FreeBSD freebsd 13.0-CURRENT FreeBSD 13.0-CURRENT #3: Thu Feb 20
03:35:37 UTC 2020
root@freebsd:/usr/obj/usr/src/amd64.amd64/sys/GENERIC  amd64

panic: Most recently used by GEOM

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Reading symbols from /boot/kernel/kernel...
Reading symbols from /usr/lib/debug//boot/kernel/kernel.debug...

Unread portion of the kernel message buffer:
Superblock check-hash failed: recorded check-hash 0x9dafc69a !=
computed check-hash 0x7ccaabd4 (Ignored)
Memory modified after free 0xfffffe003a559000(65528) val=4 @ 0xfffffe003a559000
panic: Most recently used by GEOM

cpuid = 1
time = 1582268274
KDB: stack backtrace:
db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 0xfffffe002c779750
vpanic() at vpanic+0x185/frame 0xfffffe002c7797b0
panic() at panic+0x43/frame 0xfffffe002c779810
mtrash_ctor() at mtrash_ctor+0x7e/frame 0xfffffe002c779830
item_ctor() at item_ctor+0x2cb/frame 0xfffffe002c779890
uma_zalloc_arg() at uma_zalloc_arg+0x144/frame 0xfffffe002c7798e0
malloc() at malloc+0x99/frame 0xfffffe002c779930
g_read_data() at g_read_data+0x82/frame 0xfffffe002c779970
g_use_g_read_data() at g_use_g_read_data+0x35/frame 0xfffffe002c779990
ffs_sbget() at ffs_sbget+0x24f/frame 0xfffffe002c779a00
g_label_ufs_taste_common() at g_label_ufs_taste_common+0x79/frame
0xfffffe002c779a40
g_label_taste() at g_label_taste+0x2ac/frame 0xfffffe002c779b50
g_new_provider_event() at g_new_provider_event+0xaa/frame 0xfffffe002c779b70
g_run_events() at g_run_events+0x176/frame 0xfffffe002c779bb0
fork_exit() at fork_exit+0x80/frame 0xfffffe002c779bf0
fork_trampoline() at fork_trampoline+0xe/frame 0xfffffe002c779bf0
--- trap 0, rip = 0, rsp = 0, rbp = 0 ---
KDB: enter: panic
Uptime: 6m11s
Dumping 264 out of 4062 MB:..7%..13%..25%..31%..43%..55%..61%..73%..85%..91%

[Attachments]
+ UFS filesystem image
+ detailed logs from FreeBSD 13-CURRENT, 12.1-RELEASE, and 12.1-STABLE.