Bug 1226991 (CVE-2024-39467)

Summary: VUL-0: CVE-2024-39467: kernel: f2fs: fix to do sanity check on i_xattr_nid in sanity_check_inode()
Product: [Novell Products] SUSE Security Incidents Reporter: SMASH SMASH <smash_bz>
Component: IncidentsAssignee: Kernel Bugs <kernel-bugs>
Status: RESOLVED INVALID QA Contact: Security Team bot <security-team>
Severity: Normal    
Priority: P3 - Medium CC: carlos.lopez
Version: unspecified   
Target Milestone: ---   
Hardware: Other   
OS: Other   
URL: https://smash.suse.de/issue/412089/
Whiteboard: CVSSv3.1:SUSE:CVE-2024-39467:5.5:(AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H)
Found By: Security Response Team Services Priority:
Business Priority: Blocker: ---
Marketing QA Status: --- IT Deployment: ---

Description SMASH SMASH 2024-06-26 07:49:55 UTC 
In the Linux kernel, the following vulnerability has been resolved:

f2fs: fix to do sanity check on i_xattr_nid in sanity_check_inode()

syzbot reports a kernel bug as below:

F2FS-fs (loop0): Mounted with checkpoint version = 48b305e4
==================================================================
BUG: KASAN: slab-out-of-bounds in f2fs_test_bit fs/f2fs/f2fs.h:2933 [inline]
BUG: KASAN: slab-out-of-bounds in current_nat_addr fs/f2fs/node.h:213 [inline]
BUG: KASAN: slab-out-of-bounds in f2fs_get_node_info+0xece/0x1200 fs/f2fs/node.c:600
Read of size 1 at addr ffff88807a58c76c by task syz-executor280/5076

CPU: 1 PID: 5076 Comm: syz-executor280 Not tainted 6.9.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 f2fs_test_bit fs/f2fs/f2fs.h:2933 [inline]
 current_nat_addr fs/f2fs/node.h:213 [inline]
 f2fs_get_node_info+0xece/0x1200 fs/f2fs/node.c:600
 f2fs_xattr_fiemap fs/f2fs/data.c:1848 [inline]
 f2fs_fiemap+0x55d/0x1ee0 fs/f2fs/data.c:1925
 ioctl_fiemap fs/ioctl.c:220 [inline]
 do_vfs_ioctl+0x1c07/0x2e50 fs/ioctl.c:838
 __do_sys_ioctl fs/ioctl.c:902 [inline]
 __se_sys_ioctl+0x81/0x170 fs/ioctl.c:890
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The root cause is we missed to do sanity check on i_xattr_nid during
f2fs_iget(), so that in fiemap() path, current_nat_addr() will access
nat_bitmap w/ offset from invalid i_xattr_nid, result in triggering
kasan bug report, fix it.

References:
http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2024-39467
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2024/CVE-2024-39467.mbox
https://git.kernel.org/stable/c/c559a8d840562fbfce9f318448dda2f7d3e6d8e8
https://git.kernel.org/stable/c/75c87e2ac6149abf44bdde0dd6d541763ddb0dff
https://git.kernel.org/stable/c/1640dcf383cdba52be8b28d2a1a2aa7ef7a30c98
https://git.kernel.org/stable/c/8c8aa473fe6eb46a4bf99f3ea2dbe52bf0c1a1f0
https://git.kernel.org/stable/c/be0155202e431f3007778568a72432c68f8946ba
https://git.kernel.org/stable/c/68e3cd4ecb8603936cccdc338929130045df2e57
https://git.kernel.org/stable/c/20faaf30e55522bba2b56d9c46689233205d7717
https://www.cve.org/CVERecord?id=CVE-2024-39467
https://bugzilla.redhat.com/show_bug.cgi?id=2294305
Comment 1 Carlos López 2024-06-26 07:50:27 UTC 
f2fs not supported in our kernels, closing.