strsep() modifies the address of the pointer passed to it so that it no
longer points to the original address. This means kfree() gets the wrong
pointer.

Fix this by passing unmodified pointer returned from kstrdup() to kfree().

Found by Linux Verification Center (linuxtesting.org) with Svace.

Fixes: 4df84e846624 ("scsi: elx: efct: Driver initialization routines")
Signed-off-by: Vitaliy Shevtsov <v.shevtsov@mt-integration.ru>
---
 drivers/scsi/elx/efct/efct_hw.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/elx/efct/efct_hw.c b/drivers/scsi/elx/efct/efct_hw.c
index 5a5525054d71..5b079b8b7a08 100644
--- a/drivers/scsi/elx/efct/efct_hw.c
+++ b/drivers/scsi/elx/efct/efct_hw.c
@@ -1120,7 +1120,7 @@ int
 efct_hw_parse_filter(struct efct_hw *hw, void *value)
 {
 	int rc = 0;
-	char *p = NULL;
+	char *p = NULL, *pp = NULL;
 	char *token;
 	u32 idx = 0;
 
@@ -1132,6 +1132,7 @@ efct_hw_parse_filter(struct efct_hw *hw, void *value)
 		efc_log_err(hw->os, "p is NULL\n");
 		return -ENOMEM;
 	}
+	pp = p;
 
 	idx = 0;
 	while ((token = strsep(&p, ",")) && *token) {
@@ -1144,7 +1145,7 @@ efct_hw_parse_filter(struct efct_hw *hw, void *value)
 		if (idx == ARRAY_SIZE(hw->config.filter_def))
 			break;
 	}
-	kfree(p);
+	kfree(pp);
 
 	return rc;
 }
-- 
2.49.0

On Thu, Jun 12, 2025 at 09:35:18PM +0500, Vitaliy Shevtsov wrote:
> strsep() modifies the address of the pointer passed to it so that it no
> longer points to the original address. This means kfree() gets the wrong
> pointer.
> 
> Fix this by passing unmodified pointer returned from kstrdup() to kfree().
> 
> Found by Linux Verification Center (linuxtesting.org) with Svace.
> 
> Fixes: 4df84e846624 ("scsi: elx: efct: Driver initialization routines")
> Signed-off-by: Vitaliy Shevtsov <v.shevtsov@mt-integration.ru>

Reviewed-by: Daniel Wagner <dwagner@suse.de>