From: K Prateek Nayak <kprateek.nayak@xxxxxxx>
[ Upstream commit cf3d0c54b21c4a351d4f94cf188e9715dbd1ef5b ]
Limit the number of slots in pipe_resize_ring() to the maximum value
representable by pipe->{head,tail}. Values beyond the max limit can
lead to incorrect pipe occupancy related calculations where the pipe
will never appear full.
Suggested-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: K Prateek Nayak <kprateek.nayak@xxxxxxx>
Link: https://lore.kernel.org/r/20250307052919.34542-2-kprateek.nayak@xxxxxxx
Reviewed-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Signed-off-by: Christian Brauner <brauner@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
fs/pipe.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/fs/pipe.c b/fs/pipe.c
index 4d0799e4e7196..88e81f84e3eaf 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -1271,6 +1271,10 @@ int pipe_resize_ring(struct pipe_inode_info *pipe, unsigned int nr_slots)
struct pipe_buffer *bufs;
unsigned int head, tail, mask, n;
+ /* nr_slots larger than limits of pipe->{head,tail} */
+ if (unlikely(nr_slots > (pipe_index_t)-1u))
+ return -EINVAL;
+
bufs = kcalloc(nr_slots, sizeof(*bufs),
GFP_KERNEL_ACCOUNT | __GFP_NOWARN);
if (unlikely(!bufs))
--
2.39.5
