Kernel/linux-next
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git synced 2024-12-29 09:12:07 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

fuse: Set *nbytesp=0 in fuse_get_user_pages on allocation failure

Browse Source 
In fuse_get_user_pages(), set *nbytesp to 0 when struct page **pages
allocation fails. This prevents the caller (fuse_direct_io) from making
incorrect assumptions that could lead to NULL pointer dereferences
when processing the request reply.

Previously, *nbytesp was left unmodified on allocation failure, which
could cause issues if the caller assumed pages had been added to
ap->descs[] when they hadn't.

Reported-by: syzbot+87b8e6ed25dbc41759f7@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=87b8e6ed25dbc41759f7
Fixes: 3b97c3652d ("fuse: convert direct io to use folios")
Signed-off-by: Bernd Schubert <bschubert@ddn.com>
Reviewed-by: Joanne Koong <joannelkoong@gmail.com>
Tested-by: Dmitry Antipov <dmantipov@yandex.ru>
Tested-by: David Howells <dhowells@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
This commit is contained in:
Bernd Schubert 2024-12-03 00:01:10 +01:00 committed by Miklos Szeredi
parent 7a4f541873
commit 78f2560fc9
1 changed files with 5 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
fs/fuse/file.c
View File

@ -1541,8 +1541,10 @@ static int fuse_get_user_pages(struct fuse_args_pages *ap, struct iov_iter *ii,
*/
struct page **pages = kzalloc(max_pages * sizeof(struct page *),
GFP_KERNEL);
if (!pages)
return -ENOMEM;
if (!pages) {
ret = -ENOMEM;
goto out;
}
while (nbytes < *nbytesp && nr_pages < max_pages) {
unsigned nfolios, i;
@ -1588,6 +1590,7 @@ static int fuse_get_user_pages(struct fuse_args_pages *ap, struct iov_iter *ii,
else
ap->args.out_pages = true;
out:
*nbytesp = nbytes;
return ret < 0 ? ret : 0;