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authorJia-Ju Bai <baijiaju1990@gmail.com>2019-07-30 14:38:51 +0100
committerDavid Howells <dhowells@redhat.com>2019-07-30 14:38:51 +0100
commita6eed4ab5dd4bfb696c1a3f49742b8d1846a66a0 (patch)
treef6980f4599da0a64b9670f6111b4fccf318d0c66 /fs/afs/file.c
parent4a46fdba449a5cd890271df5a9e23927d519ed00 (diff)
fs: afs: Fix a possible null-pointer dereference in afs_put_read()
In afs_read_dir(), there is an if statement on line 255 to check whether req->pages is NULL: if (!req->pages) goto error; If req->pages is NULL, afs_put_read() on line 337 is executed. In afs_put_read(), req->pages[i] is used on line 195. Thus, a possible null-pointer dereference may occur in this case. To fix this possible bug, an if statement is added in afs_put_read() to check req->pages. This bug is found by a static analysis tool STCheck written by us. Fixes: f3ddee8dc4e2 ("afs: Fix directory handling") Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com>
Diffstat (limited to 'fs/afs/file.c')
-rw-r--r--fs/afs/file.c12
1 files changed, 7 insertions, 5 deletions
diff --git a/fs/afs/file.c b/fs/afs/file.c
index 56b69576274d..dd3c55c9101c 100644
--- a/fs/afs/file.c
+++ b/fs/afs/file.c
@@ -191,11 +191,13 @@ void afs_put_read(struct afs_read *req)
int i;
if (refcount_dec_and_test(&req->usage)) {
- for (i = 0; i < req->nr_pages; i++)
- if (req->pages[i])
- put_page(req->pages[i]);
- if (req->pages != req->array)
- kfree(req->pages);
+ if (req->pages) {
+ for (i = 0; i < req->nr_pages; i++)
+ if (req->pages[i])
+ put_page(req->pages[i]);
+ if (req->pages != req->array)
+ kfree(req->pages);
+ }
kfree(req);
}
}