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:

? __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...

Classification

CVE ID: CVE-2024-26868

Affected Products

Vendor: Linux

Product: Linux

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.04% (probability of being exploited)

EPSS Percentile: 5.08% (scored less or equal to compared to others)

EPSS Date: 2025-02-04 (when was this score calculated)

References

https://git.kernel.org/stable/c/31db25e3141b20e2a76a9f219eeca52e3cab126c
https://git.kernel.org/stable/c/7ca651b4ec4a049f5a46a0e5ff921b86b91c47c5
https://git.kernel.org/stable/c/5ada9016b1217498fad876a3d5b07645cc955608
https://git.kernel.org/stable/c/dac068f164ad05b35e7c0be13f138c3f6adca58f
https://git.kernel.org/stable/c/719fcafe07c12646691bd62d7f8d94d657fa0766

Timeline