diff options
| author | Mohsin Bashir <mohsin.bashr@gmail.com> | 2025-11-25 13:17:04 -0800 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2025-11-26 18:25:52 -0800 |
| commit | 6d66e093e0740d39a36ef742c60eec247df26f41 (patch) | |
| tree | 76b7a78b7aca72c814c6fdd8cfe537ac745a8dfd /drivers | |
| parent | 27fd02860164bfa78cec2640dfad630d832e302c (diff) | |
| download | net-6d66e093e0740d39a36ef742c60eec247df26f41.tar.gz | |
eth: fbnic: Fix counter roll-over issue
Fix a potential counter roll-over issue in fbnic_mbx_alloc_rx_msgs()
when calculating descriptor slots. The issue occurs when head - tail
results in a large positive value (unsigned) and the compiler interprets
head - tail - 1 as a signed value.
Since FBNIC_IPC_MBX_DESC_LEN is a power of two, use a masking operation,
which is a common way of avoiding this problem when dealing with these
sort of ring space calculations.
Fixes: da3cde08209e ("eth: fbnic: Add FW communication mechanism")
Signed-off-by: Mohsin Bashir <mohsin.bashr@gmail.com>
Link: https://patch.msgid.link/20251125211704.3222413-1-mohsin.bashr@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/net/ethernet/meta/fbnic/fbnic_fw.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_fw.c b/drivers/net/ethernet/meta/fbnic/fbnic_fw.c index c87cb9ed09e7e2..fcd9912e7ad3bd 100644 --- a/drivers/net/ethernet/meta/fbnic/fbnic_fw.c +++ b/drivers/net/ethernet/meta/fbnic/fbnic_fw.c @@ -201,7 +201,7 @@ static int fbnic_mbx_alloc_rx_msgs(struct fbnic_dev *fbd) return -ENODEV; /* Fill all but 1 unused descriptors in the Rx queue. */ - count = (head - tail - 1) % FBNIC_IPC_MBX_DESC_LEN; + count = (head - tail - 1) & (FBNIC_IPC_MBX_DESC_LEN - 1); while (!err && count--) { struct fbnic_tlv_msg *msg; |