| Message ID | 20240620120101.419437-1-qq810974084@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [V3] scsi: lpfc: Fix a possible null pointer dereference | expand |
Hi Huai-Yuan,
Sorry for noticing this later, but a return len while len is 0 would
result in a silent $(cat /sys/class/scsi_host/host*/lpfc_xcvr_data).
Perhaps, it's better to log something to at least notify the user why
SFP information was not able to be collected.
How about something like this?
/* Get transceiver information */
rdp_context = kmalloc(sizeof(*rdp_context), GFP_KERNEL);
+ if (!rdp_context) {
+ len = scnprintf(buf, PAGE_SIZE - len,
+ "SFP info NA: alloc failure\n");
+ return len;
+ }
rc = lpfc_get_sfp_info_wait(phba, rdp_context);
if (rc) {
Thanks,
Justin Tee
diff --git a/drivers/scsi/lpfc/lpfc_attr.c b/drivers/scsi/lpfc/lpfc_attr.c index a46c73e8d7c4..7d1e38ea9e52 100644 --- a/drivers/scsi/lpfc/lpfc_attr.c +++ b/drivers/scsi/lpfc/lpfc_attr.c @@ -1907,6 +1907,8 @@ lpfc_xcvr_data_show(struct device *dev, struct device_attribute *attr, /* Get transceiver information */ rdp_context = kmalloc(sizeof(*rdp_context), GFP_KERNEL); + if (!rdp_context) + return len; rc = lpfc_get_sfp_info_wait(phba, rdp_context); if (rc) {
In function lpfc_xcvr_data_show, the memory allocation with kmalloc might fail, thereby making rdp_context a null pointer. In the following context and functions that use this pointer, there are dereferencing operations, leading to null pointer dereference. To fix this issue, a null pointer check should be added. If it is null, just return len. Fixes: 479b0917e447 ("scsi: lpfc: Create a sysfs entry called lpfc_xcvr_data for transceiver info") Signed-off-by: Huai-Yuan Liu <qq810974084@gmail.com> --- V2: * In patch V2, we have removed the unnecessary 'out of memory' message. Thank Bart Van Assche for helpful advice. V3: * In patch V3, we return len directly instead of goto out_free_rdp. Thanks to Justin Tee for his suuestion. --- drivers/scsi/lpfc/lpfc_attr.c | 2 ++ 1 file changed, 2 insertions(+)