CVE-2024-35901

In the Linux kernel, the following vulnerability has been resolved:

net: mana: Fix Rx DMA datasize and skb_over_panic

mana_get_rxbuf_cfg() aligns the RX buffers DMA datasize to be multiple of 64. So a packet slightly bigger than mtu+14, say 1536, can be received and cause skb_over_panic.

Sample dmesg: [ 5325.237162] skbuff: skb_over_panic: text:ffffffffc043277a len:1536 put:1536 head:ff1100018b517000 data:ff1100018b517100 tail:0x700 end:0x6ea dev: [ 5325.243689] ————[ cut here ]———— [ 5325.245748] kernel BUG at net/core/skbuff.c:192! [ 5325.247838] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI [ 5325.258374] RIP: 0010:skb_panic+0x4f/0x60 [ 5325.302941] Call Trace: [ 5325.304389] [ 5325.315794] ? skb_panic+0x4f/0x60 [ 5325.317457] ? asm_exc_invalid_op+0x1f/0x30 [ 5325.319490] ? skb_panic+0x4f/0x60 [ 5325.321161] skb_put+0x4e/0x50 [ 5325.322670] mana_poll+0x6fa/0xb50 [mana] [ 5325.324578] __napi_poll+0x33/0x1e0 [ 5325.326328] net_rx_action+0x12e/0x280

As discussed internally, this alignment is not necessary. To fix this bug, remove it from the code. So oversized packets will be marked as CQE_RX_TRUNCATED by NIC, and dropped.

Weakness

The product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse.

Affected Software

Potential Mitigations

• Choose a language or tool that provides automatic memory management, or makes manual memory management less error-prone.
• For example, glibc in Linux provides protection against free of invalid pointers.
• When using Xcode to target OS X or iOS, enable automatic reference counting (ARC) [REF-391].
• To help correctly and consistently manage memory when programming in C++, consider using a smart pointer class such as std::auto_ptr (defined by ISO/IEC ISO/IEC 14882:2003), std::shared_ptr and std::unique_ptr (specified by an upcoming revision of the C++ standard, informally referred to as C++ 1x), or equivalent solutions such as Boost.

References

• https://git.kernel.org/stable/c/05cb7c41fa1a7a7b2c2a6b81bbe7c67f5c11932b
• https://git.kernel.org/stable/c/c0de6ab920aafb56feab56058e46b688e694a246
• https://git.kernel.org/stable/c/ca58927b00385005f488b6a9905ced7a4f719aad
• https://git.kernel.org/stable/c/05cb7c41fa1a7a7b2c2a6b81bbe7c67f5c11932b
• https://git.kernel.org/stable/c/c0de6ab920aafb56feab56058e46b688e694a246
• https://git.kernel.org/stable/c/ca58927b00385005f488b6a9905ced7a4f719aad