6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Carlos López <clopez@xxxxxxx>
[ Upstream commit 8e64d2356cbc800b4cd0e3e614797f76bcf0cdb8 ]
dasd_add_busid() can return an error via ERR_PTR() if an allocation
fails. However, two callsites in dasd_copy_pair_store() do not check
the result, potentially resulting in a NULL pointer dereference. Fix
this by checking the result with IS_ERR() and returning the error up
the stack.
Fixes: a91ff09d39f9b ("s390/dasd: add copy pair setup")
Signed-off-by: Carlos López <clopez@xxxxxxx>
Signed-off-by: Stefan Haberland <sth@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20240715112434.2111291-3-sth@xxxxxxxxxxxxx
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/s390/block/dasd_devmap.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/drivers/s390/block/dasd_devmap.c b/drivers/s390/block/dasd_devmap.c
index c4e36650c4264..91522dba9fd98 100644
--- a/drivers/s390/block/dasd_devmap.c
+++ b/drivers/s390/block/dasd_devmap.c
@@ -2258,13 +2258,19 @@ static ssize_t dasd_copy_pair_store(struct device *dev,
/* allocate primary devmap if needed */
prim_devmap = dasd_find_busid(prim_busid);
- if (IS_ERR(prim_devmap))
+ if (IS_ERR(prim_devmap)) {
prim_devmap = dasd_add_busid(prim_busid, DASD_FEATURE_DEFAULT);
+ if (IS_ERR(prim_devmap))
+ return PTR_ERR(prim_devmap);
+ }
/* allocate secondary devmap if needed */
sec_devmap = dasd_find_busid(sec_busid);
- if (IS_ERR(sec_devmap))
+ if (IS_ERR(sec_devmap)) {
sec_devmap = dasd_add_busid(sec_busid, DASD_FEATURE_DEFAULT);
+ if (IS_ERR(sec_devmap))
+ return PTR_ERR(sec_devmap);
+ }
/* setting copy relation is only allowed for offline secondary */
if (sec_devmap->device)
--
2.43.0
