Description

In the Linux kernel, the following vulnerability has been resolved: batman-adv: tvlv: reject oversized TVLV packets batadv_tvlv_container_ogm_append() builds a TVLV packet section from the tvlv.container_list. The total size of this section is computed by batadv_tvlv_container_list_size(), which sums the sizes of all registered containers. The return type and accumulator in batadv_tvlv_container_list_size() were u16. If the accumulated size exceeds U16_MAX, the value wraps around, causing the subsequent allocation in batadv_tvlv_container_ogm_append() to be undersized. The memcpy-style copy that follows would then write beyond the end of the allocated buffer, corrupting kernel memory. Fix this by widening the return type of batadv_tvlv_container_list_size() to size_t. In batadv_tvlv_container_ogm_append(), check the computed length against U16_MAX before proceeding, and bail out as if the allocation had failed when the limit is exceeded.

References 8

• git.kernel.org https://git.kernel.org/stable/c/13493b00dd1e05a705981e052158652ea23eb482
• git.kernel.org https://git.kernel.org/stable/c/1595628a2f877d052eda18865ccf539392c47c04
• git.kernel.org https://git.kernel.org/stable/c/6448a49344e87487b61bd88cb850cd694a0f576d
• git.kernel.org https://git.kernel.org/stable/c/94a3d72cd9b21116d7c6d5bdc57c11401fc28557
• git.kernel.org https://git.kernel.org/stable/c/94db72e9dac202e017ee3db22c59d17e4f3bf171
• git.kernel.org https://git.kernel.org/stable/c/c02aa6c0c9d1bea9bb75dea362b75ad225137bae
• git.kernel.org https://git.kernel.org/stable/c/ede47988ac5687793745b17c1634a496a2299919
• git.kernel.org https://git.kernel.org/stable/c/f50487e3566358b2b982b7801945e858c78ad9ab

Remediation