Tracker / CVE-2026-53392
CVE-2026-53392
In the Linux kernel, the following vulnerability has been resolved: NFSv4/flexfiles: reject zero filehandle version count ff_layout_alloc_lseg() decodes the filehandle-version array count from the flexfiles layout body. The value is used as the count for kzalloc_objs(), and the current code only rejects NULL. A zero count yields ZERO_SIZE_PTR, which can be stored in dss_info->fh_versions even though later flexfiles paths assume that at least one filehandle version exists. Reject fh_count == 0 before the allocation, matching the existing zero version_count validation in the flexfiles GETDEVICEINFO parser. A QEMU/KASAN run with a malformed flexfiles layout hit: KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] RIP: 0010:ff_layout_encode_ff_layoutupdate.isra.0+0x15f/0x750 ff_layout_encode_layoutreturn+0x683/0x970 nfs4_xdr_enc_layoutreturn+0x278/0x3a0 Kernel panic - not syncing: Fatal exception The patched kernel rejects the malformed layout without KASAN/oops/panic, and a valid fh_count=1 regression still opens, reads, and unmounts cleanly.
Affected products and versions
| linux | linux_kernel · 4.0 → 5.10.261 |
|---|---|
| linux | linux_kernel · 5.11 → 5.15.212 |
| linux | linux_kernel · 5.16 → 6.1.178 |
| linux | linux_kernel · 6.13 → 6.18.38 |
| linux | linux_kernel · 6.19 → 7.1.3 |
| linux | linux_kernel · 6.2 → 6.6.145 |
| linux | linux_kernel · 6.7 → 6.12.96 |