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| author |   Jia-Ju Bai <baijiaju1990@gmail.com> | 2019-07-30 14:38:51 +0100 |
|---|---|---|
| committer |   David Howells <dhowells@redhat.com> | 2019-07-30 14:38:51 +0100 |
| commit | a6eed4ab5dd4bfb696c1a3f49742b8d1846a66a0 (patch) | |
| tree | f6980f4599da0a64b9670f6111b4fccf318d0c66 /fs/afs | |
| parent | afs: Fix loop index mixup in afs_deliver_vl_get_entry_by_name_u() (diff) | |
| download | wireguard-linux-a6eed4ab5dd4bfb696c1a3f49742b8d1846a66a0.tar.xz wireguard-linux-a6eed4ab5dd4bfb696c1a3f49742b8d1846a66a0.zip | |
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')
| -rw-r--r-- | fs/afs/file.c | 12 |
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); } } |