From: Michael Chan michael.chan@broadcom.com
[ Upstream commit bbd6f0a948139970f4a615dff189d9a503681a39 ]
In bnxt_rx_pkt(), the RX buffers are expected to complete in order. If the RX consumer index indicates an out of order buffer completion, it means we are hitting a hardware bug and the driver will abort all remaining RX packets and reset the RX ring. The RX consumer index that we pass to bnxt_discard_rx() is not correct. We should be passing the current index (tmp_raw_cons) instead of the old index (raw_cons). This bug can cause us to be at the wrong index when trying to abort the next RX packet. It can crash like this:
#0 [ffff9bbcdf5c39a8] machine_kexec at ffffffff9b05e007 #1 [ffff9bbcdf5c3a00] __crash_kexec at ffffffff9b111232 #2 [ffff9bbcdf5c3ad0] panic at ffffffff9b07d61e #3 [ffff9bbcdf5c3b50] oops_end at ffffffff9b030978 #4 [ffff9bbcdf5c3b78] no_context at ffffffff9b06aaf0 #5 [ffff9bbcdf5c3bd8] __bad_area_nosemaphore at ffffffff9b06ae2e #6 [ffff9bbcdf5c3c28] bad_area_nosemaphore at ffffffff9b06af24 #7 [ffff9bbcdf5c3c38] __do_page_fault at ffffffff9b06b67e #8 [ffff9bbcdf5c3cb0] do_page_fault at ffffffff9b06bb12 #9 [ffff9bbcdf5c3ce0] page_fault at ffffffff9bc015c5 [exception RIP: bnxt_rx_pkt+237] RIP: ffffffffc0259cdd RSP: ffff9bbcdf5c3d98 RFLAGS: 00010213 RAX: 000000005dd8097f RBX: ffff9ba4cb11b7e0 RCX: ffffa923cf6e9000 RDX: 0000000000000fff RSI: 0000000000000627 RDI: 0000000000001000 RBP: ffff9bbcdf5c3e60 R8: 0000000000420003 R9: 000000000000020d R10: ffffa923cf6ec138 R11: ffff9bbcdf5c3e83 R12: ffff9ba4d6f928c0 R13: ffff9ba4cac28080 R14: ffff9ba4cb11b7f0 R15: ffff9ba4d5a30000 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018
Fixes: a1b0e4e684e9 ("bnxt_en: Improve RX consumer index validity check.") Reviewed-by: Pavan Chebbi pavan.chebbi@broadcom.com Reviewed-by: Andy Gospodarek gospo@broadcom.com Signed-off-by: Michael Chan michael.chan@broadcom.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/broadcom/bnxt/bnxt.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c index 11839f086f29..f3c659bc6bb6 100644 --- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c @@ -1731,14 +1731,16 @@ static int bnxt_rx_pkt(struct bnxt *bp, struct bnxt_cp_ring_info *cpr,
cons = rxcmp->rx_cmp_opaque; if (unlikely(cons != rxr->rx_next_cons)) { - int rc1 = bnxt_discard_rx(bp, cpr, raw_cons, rxcmp); + int rc1 = bnxt_discard_rx(bp, cpr, &tmp_raw_cons, rxcmp);
/* 0xffff is forced error, don't print it */ if (rxr->rx_next_cons != 0xffff) netdev_warn(bp->dev, "RX cons %x != expected cons %x\n", cons, rxr->rx_next_cons); bnxt_sched_reset(bp, rxr); - return rc1; + if (rc1) + return rc1; + goto next_rx_no_prod_no_len; } rx_buf = &rxr->rx_buf_ring[cons]; data = rx_buf->data;