From 47fe91b54c9c2d844059d50cb9622d7bbde9da27 Mon Sep 17 00:00:00 2001 From: Boris Protopopov Date: Fri, 30 Aug 2013 12:12:45 -0700 Subject: [PATCH] Illumos #4088 use after free in arc_release() 4088 use after free in arc_release() Reviewed by: Matthew Ahrens Reviewed by: Garrett D'Amore Reviewed by: Saso Kiselkov Approved by: Dan McDonald References: https://www.illumos.org/issues/4088 illumos/illumos-gate@ccc22e130479b5bd7c0002267fee1e0602d3f772 From the illumos issue: A race-induced use after free occurs in arc_release() where the ARC header is used outside the critical section protected by the hash_lock. Ported by: Tim Chase Signed-off-by: Brian Behlendorf Signed-off-by: Richard Yao Closes #2162 --- module/zfs/arc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/module/zfs/arc.c b/module/zfs/arc.c index ccc9510fd..59e6c5bc8 100644 --- a/module/zfs/arc.c +++ b/module/zfs/arc.c @@ -3665,6 +3665,7 @@ arc_release(arc_buf_t *buf, void *tag) if (l2hdr) { mutex_enter(&l2arc_buflist_mtx); hdr->b_l2hdr = NULL; + list_remove(l2hdr->b_dev->l2ad_buflist, hdr); } buf_size = hdr->b_size; @@ -3758,7 +3759,6 @@ arc_release(arc_buf_t *buf, void *tag) if (l2hdr) { ARCSTAT_INCR(arcstat_l2_asize, -l2hdr->b_asize); - list_remove(l2hdr->b_dev->l2ad_buflist, hdr); kmem_cache_free(l2arc_hdr_cache, l2hdr); arc_space_return(L2HDR_SIZE, ARC_SPACE_L2HDRS); ARCSTAT_INCR(arcstat_l2_size, -buf_size); -- 2.39.2