In the Linux kernel, the following vulnerability has been resolved:
bnxt_en: Bound SW TPA IDs to prevent crashes
FW supports up to 1024 concurrent TPAs, so the FW TPA ID is in the range
0..1023 (see commit ec4d8e7cf024 ("bnxt_en: Add TPA ID mapping logic for
57500 chips.")). bnxt_alloc_agg_idx is intended to wrap the FW ID down to a
software ID which is used to index rxr->rx_tpa, and to generate a mapping
between FW IDs and the wrapped software ID.
On a 57608 with firmware version 233, the firmware advertises 32
concurrent TPAs. As of the commit under fixes, bp->max_tpa on this NIC
is set to 32.
If the software ID from bnxt_alloc_agg_idx is above 31, this results in
an invalid address being loaded on this line:
tpa_info = &rxr->rx_tpa[agg_id];
because rx_tpa is allocated with only bp->max_tpa (32) entries. Writes
to tpa_info later in the code are out of bounds.
This bug results in a crash at boot:
Oops: general protection fault, kernel NULL pointer dereference 0x8: 0000 [#1] SMP NOPTI
RIP: 0010:bnxt_rx_pkt+0xc0/0x1560
RSP: 0018:ffffc900009b8c78 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000048 RCX: 0000000206682516
RDX: ffffc900009b8db4 RSI: 0000000000000000 RDI: 01ffffff038fe1c0
RBP: ffffc9006e687480 R08: ffffc9006e687000 R09: 0000000000003048
R10: 0000000000000480 R11: ffff8881c6083900 R12: 0000000006682516
R13: ffff8881c6095400 R14: 0000000000000016 R15: ffff8881c6b66680
FS: 0000000000000000(0000) GS:ffff88fef3c77000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc8bda40584 CR3: 000000807c812001 CR4: 0000000008772ef0
PKRU: 55555554
Call Trace:
Unknown