staging: android: ion: Switch to pr_warn_once in ion_buffer_destroy
PATCH 1/1 staging: android: ion: Switch to pr_warn_once in ion_buffer_destroy
Syzbot reported yet another warning with Ion:
WARNING: CPU: 0 PID: 1467 at drivers/staging/android/ion/ion.c:122 ion_buffer_destroy+0xd4/0x190 drivers/staging/android/ion/ion.c:122 Kernel panic - not syncing: panic_on_warn set ...
This is catching that a buffer was freed with an existing kernel mapping still present. This can be easily be triggered from userspace by calling DMA_BUF_SYNC_START without calling DMA_BUF_SYNC_END. Switch to a single pr_warn_once to indicate the error without being disruptive.
Reported-by [email protected]
Reported-by syzbot <[email protected]>
Signed-off-by Laura Abbott <[email protected]>
Cc stable <[email protected]>
--- drivers/staging/android/ion/ion.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
drivers/staging/android/ion/ion.c +4 -1
@@ -114,8 +114,11 @@ static struct ion_buffer *ion_buffer_create(struct ion_heap *heap,void ion_buffer_destroy (struct ion_buffer *buffer) { -if (WARN_ON (buffer->kmap_cnt >0 )) +if (buffer->kmap_cnt >0 ) { +pr_warn_once ("%s: buffer still mapped in the kernel\n" , + __func__); buffer->heap->ops->unmap_kernel (buffer->heap, buffer); + } buffer->heap->ops->free (buffer);kfree (buffer); }
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