In the Linux kernel, the following vulnerability has been resolved:
qede: Fix NULL pointer dereference in TPA fragment processing
Under memory pressure, the qede driver encounters NULL pointer
dereferences when processing TPA continuation fragments. Commit 8a8633978b84 ("qede: Add build_skb() support.") accidentally
dropped the assignment of tpa_info->buffer.data in qede_tpa_start(). When memory pressure causes an SKB allocation failure in qede_tpa_start(),
the driver sets tpa_start_fail = true and attempts to recycle the physical
page later in qede_tpa_end() via qede_reuse_page().
However, because
buffer.data was left uninitialized (NULL), qede_reuse_page() pushes a
"ghost" BD (valid DMA mapping but NULL data pointer) back into the
active Rx ring. The next time the hardware uses this ring slot, it passes a NULL page
to qede_fill_frag_skb(), causing a kernel panic. Example crash from production system:
BUG: unable to handle kernel NULL pointer dereference at 0x8
RIP: qede_fill_frag_skb+0x96/0x430 [qede]
Call Trace:
qede_rx_int+0xb06/0x1de0
qede_poll+0x2f4/0x6c0
__napi_poll+0x2d/0x130
Fix the root cause by restoring the tpa_info->buffer.data assignment
in qede_tpa_start(), ensuring valid pages are correctly tracked and
recycled.
Additionally, update the stale comment for
struct qede_agg_info::buffer to reflect its current usage.
Attack Parameters
Impact Assessment
CVSS Vector v3.1