This is a note to let you know that I've just added the patch titled
ptr_ring: try vmalloc() when kmalloc() fails
to the 4.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: ptr_ring-try-vmalloc-when-kmalloc-fails.patch and it can be found in the queue-4.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From 0bf7800f1799b5b1fd7d4f024e9ece53ac489011 Mon Sep 17 00:00:00 2001
From: Jason Wang jasowang@redhat.com Date: Fri, 9 Feb 2018 17:45:50 +0800 Subject: ptr_ring: try vmalloc() when kmalloc() fails
From: Jason Wang jasowang@redhat.com
commit 0bf7800f1799b5b1fd7d4f024e9ece53ac489011 upstream.
This patch switch to use kvmalloc_array() for using a vmalloc() fallback to help in case kmalloc() fails.
Reported-by: syzbot+e4d4f9ddd4295539735d@syzkaller.appspotmail.com Fixes: 2e0ab8ca83c12 ("ptr_ring: array based FIFO for pointers") Signed-off-by: Jason Wang jasowang@redhat.com Acked-by: Michael S. Tsirkin mst@redhat.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- include/linux/ptr_ring.h | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-)
--- a/include/linux/ptr_ring.h +++ b/include/linux/ptr_ring.h @@ -451,11 +451,14 @@ static inline int ptr_ring_consume_batch __PTR_RING_PEEK_CALL_v; \ })
+/* Not all gfp_t flags (besides GFP_KERNEL) are allowed. See + * documentation for vmalloc for which of them are legal. + */ static inline void **__ptr_ring_init_queue_alloc(unsigned int size, gfp_t gfp) { if (size * sizeof(void *) > KMALLOC_MAX_SIZE) return NULL; - return kcalloc(size, sizeof(void *), gfp); + return kvmalloc_array(size, sizeof(void *), gfp | __GFP_ZERO); }
static inline void __ptr_ring_set_size(struct ptr_ring *r, int size) @@ -588,7 +591,7 @@ static inline int ptr_ring_resize(struct spin_unlock(&(r)->producer_lock); spin_unlock_irqrestore(&(r)->consumer_lock, flags);
- kfree(old); + kvfree(old);
return 0; } @@ -628,7 +631,7 @@ static inline int ptr_ring_resize_multip }
for (i = 0; i < nrings; ++i) - kfree(queues[i]); + kvfree(queues[i]);
kfree(queues);
@@ -636,7 +639,7 @@ static inline int ptr_ring_resize_multip
nomem: while (--i >= 0) - kfree(queues[i]); + kvfree(queues[i]);
kfree(queues);
@@ -651,7 +654,7 @@ static inline void ptr_ring_cleanup(stru if (destroy) while ((ptr = ptr_ring_consume(r))) destroy(ptr); - kfree(r->queue); + kvfree(r->queue); }
#endif /* _LINUX_PTR_RING_H */
Patches currently in stable-queue which might be from jasowang@redhat.com are
queue-4.15/ptr_ring-try-vmalloc-when-kmalloc-fails.patch queue-4.15/ptr_ring-fail-early-if-queue-occupies-more-than-kmalloc_max_size.patch