Bug 1223040 (CVE-2024-26871)

Summary: VUL-0: CVE-2024-26871: kernel: f2fs: fix NULL pointer dereference in f2fs_submit_page_write()
Product: [Novell Products] SUSE Security Incidents Reporter: SMASH SMASH <smash_bz>
Component: IncidentsAssignee: Security Team bot <security-team>
Status: RESOLVED FIXED QA Contact: Security Team bot <security-team>
Severity: Normal    
Priority: P5 - None CC: ailiopoulos, carlos.lopez
Version: unspecified   
Target Milestone: ---   
Hardware: Other   
OS: Other   
URL: https://smash.suse.de/issue/402375/
Whiteboard: CVSSv3.1:SUSE:CVE-2024-26871:5.5:(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 2024-04-18 08:38:01 UTC 
In the Linux kernel, the following vulnerability has been resolved:

f2fs: fix NULL pointer dereference in f2fs_submit_page_write()

BUG: kernel NULL pointer dereference, address: 0000000000000014
RIP: 0010:f2fs_submit_page_write+0x6cf/0x780 [f2fs]
Call Trace:
<TASK>
? show_regs+0x6e/0x80
? __die+0x29/0x70
? page_fault_oops+0x154/0x4a0
? prb_read_valid+0x20/0x30
? __irq_work_queue_local+0x39/0xd0
? irq_work_queue+0x36/0x70
? do_user_addr_fault+0x314/0x6c0
? exc_page_fault+0x7d/0x190
? asm_exc_page_fault+0x2b/0x30
? f2fs_submit_page_write+0x6cf/0x780 [f2fs]
? f2fs_submit_page_write+0x736/0x780 [f2fs]
do_write_page+0x50/0x170 [f2fs]
f2fs_outplace_write_data+0x61/0xb0 [f2fs]
f2fs_do_write_data_page+0x3f8/0x660 [f2fs]
f2fs_write_single_data_page+0x5bb/0x7a0 [f2fs]
f2fs_write_cache_pages+0x3da/0xbe0 [f2fs]
...
It is possible that other threads have added this fio to io->bio
and submitted the io->bio before entering f2fs_submit_page_write().
At this point io->bio = NULL.
If is_end_zone_blkaddr(sbi, fio->new_blkaddr) of this fio is true,
then an NULL pointer dereference error occurs at bio_get(io->bio).
The original code for determining zone end was after "out:",
which would have missed some fio who is zone end. I've moved
 this code before "skip:" to make sure it's done for each fio.

References:
http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2024-26871
https://www.cve.org/CVERecord?id=CVE-2024-26871
https://git.kernel.org/stable/c/4c122a32582b67bdd44ca8d25f894ee2dc54f566
https://git.kernel.org/stable/c/6d102382a11d5e6035f6c98f6e508a38541f7af3
https://git.kernel.org/stable/c/8e2ea8b04cb8d976110c4568509e67d6a39b2889
https://git.kernel.org/stable/c/c2034ef6192a65a986a45c2aa2ed05824fdc0e9f
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2024/CVE-2024-26871.mbox
https://bugzilla.redhat.com/show_bug.cgi?id=2275709
Comment 1 Anthony Iliopoulos 2024-04-18 08:44:13 UTC 
f2fs is completely unsupported (we don't compile it in any branch). Nothing to do here, assigning back to sec.
Comment 2 Carlos López 2024-04-18 08:49:36 UTC 
Nothing to do, closing.