CVE-2024-50276

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

net: vertexcom: mse102x: Fix possible double free of TX skb

The scope of the TX skb is wider than just mse102x_tx_frame_spi(), so in case the TX skb room needs to be expanded, we should free the the temporary skb instead of the original skb. Otherwise the original TX skb pointer would be freed again in mse102x_tx_work(), which leads to crashes:

Internal error: Oops: 0000000096000004 [#2] PREEMPT SMP CPU: 0 PID: 712 Comm: kworker/0:1 Tainted: G D 6.6.23 Hardware name: chargebyte Charge SOM DC-ONE (DT) Workqueue: events mse102x_tx_work [mse102x] pstate: 20400009 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=–) pc : skb_release_data+0xb8/0x1d8 lr : skb_release_data+0x1ac/0x1d8 sp : ffff8000819a3cc0 x29: ffff8000819a3cc0 x28: ffff0000046daa60 x27: ffff0000057f2dc0 x26: ffff000005386c00 x25: 0000000000000002 x24: 00000000ffffffff x23: 0000000000000000 x22: 0000000000000001 x21: ffff0000057f2e50 x20: 0000000000000006 x19: 0000000000000000 x18: ffff00003fdacfcc x17: e69ad452d0c49def x16: 84a005feff870102 x15: 0000000000000000 x14: 000000000000024a x13: 0000000000000002 x12: 0000000000000000 x11: 0000000000000400 x10: 0000000000000930 x9 : ffff00003fd913e8 x8 : fffffc00001bc008 x7 : 0000000000000000 x6 : 0000000000000008 x5 : ffff00003fd91340 x4 : 0000000000000000 x3 : 0000000000000009 x2 : 00000000fffffffe x1 : 0000000000000000 x0 : 0000000000000000 Call trace: skb_release_data+0xb8/0x1d8 kfree_skb_reason+0x48/0xb0 mse102x_tx_work+0x164/0x35c [mse102x] process_one_work+0x138/0x260 worker_thread+0x32c/0x438 kthread+0x118/0x11c ret_from_fork+0x10/0x20 Code: aa1303e0 97fffab6 72001c1f 54000141 (f9400660)

Weakness

The product calls free() twice on the same memory address, potentially leading to modification of unexpected memory locations.

Affected Software

Potential Mitigations

References

• https://git.kernel.org/stable/c/1325e838089da25217f4b403318a270fcdf88f34
• https://git.kernel.org/stable/c/1f26339b2ed63d1e8e18a18674fb73a392f3660e
• https://git.kernel.org/stable/c/2cf0e77f5a0aa1ff336aa71743eda55c73902187
• https://git.kernel.org/stable/c/91c9daa21f3ff8668f9e1d6c860024ce7ad64137