diff options
| author | Tyllis Xu <livelycarpet87@gmail.com> | 2026-03-14 12:01:50 -0500 |
|---|---|---|
| committer | Martin K. Petersen <martin.petersen@oracle.com> | 2026-03-19 21:42:35 -0400 |
| commit | 61d099ac4a7a8fb11ebdb6e2ec8d77f38e77362f (patch) | |
| tree | c0b6c38e56569279aec2ae05e955f4e45936a28a /drivers | |
| parent | 7a9f448d44127217fabc4065c5ba070d4e0b5d37 (diff) | |
scsi: ibmvfc: Fix OOB access in ibmvfc_discover_targets_done()
A malicious or compromised VIO server can return a num_written value in the
discover targets MAD response that exceeds max_targets. This value is
stored directly in vhost->num_targets without validation, and is then used
as the loop bound in ibmvfc_alloc_targets() to index into disc_buf[], which
is only allocated for max_targets entries. Indices at or beyond max_targets
access kernel memory outside the DMA-coherent allocation. The
out-of-bounds data is subsequently embedded in Implicit Logout and PLOGI
MADs that are sent back to the VIO server, leaking kernel memory.
Fix by clamping num_written to max_targets before storing it.
Fixes: 072b91f9c651 ("[SCSI] ibmvfc: IBM Power Virtual Fibre Channel Adapter Client Driver")
Reported-by: Yuhao Jiang <danisjiang@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Tyllis Xu <LivelyCarpet87@gmail.com>
Reviewed-by: Dave Marquardt <davemarq@linux.ibm.com>
Acked-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Link: https://patch.msgid.link/20260314170151.548614-1-LivelyCarpet87@gmail.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/scsi/ibmvscsi/ibmvfc.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/scsi/ibmvscsi/ibmvfc.c b/drivers/scsi/ibmvscsi/ibmvfc.c index a20fce04fe79..3dd2adda195e 100644 --- a/drivers/scsi/ibmvscsi/ibmvfc.c +++ b/drivers/scsi/ibmvscsi/ibmvfc.c @@ -4966,7 +4966,8 @@ static void ibmvfc_discover_targets_done(struct ibmvfc_event *evt) switch (mad_status) { case IBMVFC_MAD_SUCCESS: ibmvfc_dbg(vhost, "Discover Targets succeeded\n"); - vhost->num_targets = be32_to_cpu(rsp->num_written); + vhost->num_targets = min_t(u32, be32_to_cpu(rsp->num_written), + max_targets); ibmvfc_set_host_action(vhost, IBMVFC_HOST_ACTION_ALLOC_TGTS); break; case IBMVFC_MAD_FAILED: |