Reference page — cumulative record through Wednesday, August 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.
Linux Linux — nfs: fix panic when nfs4_ff_layout_prepare_ds() fails
AV AC PR UI S C I A CVSS EPSS %ile KEV
L L L N U N N H 5.5 .0061 46.5 —
AFFECTED
Product Versions Fixed
Linux b739a5bd9d9f18cc69dced8db128ef7206e000cd – —
Linux 6.1 – 6.1.83
TIMELINE
Feb 19 Reserved by Linux
Apr 17 Published (CNA: Linux)
Aug 4 RESCORED — CVE-2024-26868 (Linux). CVSS 7.5 → 5.5 (NVD).
Description
In the Linux kernel, the following vulnerability has been resolved:
nfs: fix panic when nfs4_ff_layout_prepare_ds() fails
We've been seeing the following panic in production
BUG: kernel NULL pointer dereference, address: 0000000000000065
PGD 2f485f067 P4D 2f485f067 PUD 2cc5d8067 PMD 0
RIP: 0010:ff_layout_cancel_io+0x3a/0x90 [nfs_layout_flexfiles]
Call Trace:
<TASK>
? __die+0x78/0xc0
? page_fault_oops+0x286/0x380
? __rpc_execute+0x2c3/0x470 [sunrpc]
? rpc_new_task+0x42/0x1c0 [sunrpc]
? exc_page_fault+0x5d/0x110
? asm_exc_page_fault+0x22/0x30
? ff_layout_free_layoutreturn+0x110/0x110 [nfs_layout_flexfiles]
? ff_layout_cancel_io+0x3a/0x90 [nfs_layout_flexfiles]
? ff_layout_cancel_io+0x6f/0x90 [nfs_layout_flexfiles]
pnfs_mark_matching_lsegs_return+0x1b0/0x360 [nfsv4]
pnfs_error_mark_layout_for_return+0x9e/0x110 [nfsv4]
? ff_layout_send_layouterror+0x50/0x160 [nfs_layout_flexfiles]
nfs4_ff_layout_prepare_ds+0x11f/0x290 [nfs_layout_flexfiles]
ff_layout_pg_init_write+0xf0/0x1f0 [nfs_layout_flexfiles]
__nfs_pageio_add_request+0x154/0x6c0 [nfs]
nfs_pageio_add_request+0x26b/0x380 [nfs]
nfs_do_writepage+0x111/0x1e0 [nfs]
nfs_writepages_callback+0xf/0x30 [nfs]
write_cache_pages+0x17f/0x380
? nfs_pageio_init_write+0x50/0x50 [nfs]
? nfs_writepages+0x6d/0x210 [nfs]
? nfs_writepages+0x6d/0x210 [nfs]
nfs_writepages+0x125/0x210 [nfs]
do_writepages+0x67/0x220
? generic_perform_write+0x14b/0x210
filemap_fdatawrite_wbc+0x5b/0x80
file_write_and_wait_range+0x6d/0xc0
nfs_file_fsync+0x81/0x170 [nfs]
? nfs_file_mmap+0x60/0x60 [nfs]
__x64_sys_fsync+0x53/0x90
do_syscall_64+0x3d/0x90
entry_SYSCALL_64_after_hwframe+0x46/0xb0
Inspecting the core with drgn I was able to pull this
>>> prog.crashed_thread().stack_trace()[0]
#0 at 0xffffffffa079657a (ff_layout_cancel_io+0x3a/0x84) in ff_layout_cancel_io at fs/nfs/flexfilelayout/flexfilelayout.c:2021:27
>>> prog.crashed_thread().stack_trace()[0]['idx']
(u32)1
>>> prog.crashed_thread().stack_trace()[0]['flseg'].mirror_array[1].mirror_ds
(struct nfs4_ff_layout_ds *)0xffffffffffffffed
This is clear from the stack trace, we call nfs4_ff_layout_prepare_ds()
which could error out initializing the mirror_ds, and then we go to
clean it all up and our check is only for if (!mirror->mirror_ds). This
is inconsistent with the rest of the users of mirror_ds, which have
if (IS_ERR_OR_NULL(mirror_ds))
to keep from tripping over this exact scenario. Fix this up in
ff_layout_cancel_io() to make sure we don't panic when we get an error.
I also spot checked all the other instances of checking mirror_ds and we
appear to be doing the correct checks everywhere, only unconditionally
dereferencing mirror_ds when we know it would be valid.
Lifecycle
Complete event history — 3 events, chronological
| Date | Event | Detail |
| February 19, 2024 | Reserved | Reserved by Linux |
| April 17, 2024 | Published | Published (CNA: Linux) |
| August 4, 2026 | RESCORED | RESCORED — CVE-2024-26868 (Linux). CVSS 7.5 → 5.5 (NVD). |
Affected
Affected products and packages — 2 rows
| Vendor | Product / Package | Ecosystem | Version introduced | Fixed |
| Linux | Linux | — | b739a5bd9d9f18cc69dced8db128ef7206e000cd | — |
| Linux | Linux | — | 6.1 | 6.1.83 |
About this page
This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2024-26868 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Wednesday, August 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.