Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: xsk: cache csum_start/csum_offset to fix TOCTOU in xsk_skb_metadata() The TX metadata area resides in the UMEM buffer which is memory-mapped and concurrently writable by userspace. In xsk_skb_metadata(), csum_start and csum_offset are read from shared memory for bounds validation, then read again for skb assignment. A malicious userspace application can race to overwrite these values between the two reads, bypassing the bounds check and causing out-of-bounds memory access during checksum computation in the transmit path. Fix this by reading csum_start and csum_offset into local variables once, then using the local copies for both validation and assignment. Note that other metadata fields (flags, launch_time) and the cached csum fields may be mutually inconsistent due to concurrent userspace writes, but this is benign: the only security-critical invariant is that each field's validated value is the same one used, which local caching guarantees.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 48eb03dd26304c24f03bdbb9382e89c8564e71df before eb778aed8a9b2381668fcb1247ae4fa011224768; affected 48eb03dd26304c24f03bdbb9382e89c8564e71df before 0dfe05b938435892875e07771170051346412df9; affected 48eb03dd26304c24f03bdbb9382e89c8564e71df before bfdfd2706d5fb2cd496a1506e680daf979309c8b; affected 48eb03dd26304c24f03bdbb9382e89c8564e71df before 22ba97ea9cc1f63a0d0244fae38057ed452b6ac7 |
| Linux / Linux | affected 6.8; unaffected 0 before 6.8; unaffected 6.12.110 through 6.12.*; unaffected 6.18.36 through 6.18.*; unaffected 7.0.13 through 7.0.*; unaffected 7.1 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/eb778aed8a9b2381668fcb1247ae4fa011224768
- https://git.kernel.org/stable/c/0dfe05b938435892875e07771170051346412df9
- https://git.kernel.org/stable/c/bfdfd2706d5fb2cd496a1506e680daf979309c8b
- https://git.kernel.org/stable/c/22ba97ea9cc1f63a0d0244fae38057ed452b6ac7
ADP enrichment
No English description supplied.
No references supplied.