4.4-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit ce96a407adef126870b3f4a1b73529dd8aa80f49 ]
hfs_bmap_free() frees the node via hfs_bnode_put(node). However, it then reads node->this when dumping error message on an error path, which may result in a use-after-free bug. This patch frees the node only when it is never again used.
Link: http://lkml.kernel.org/r/1542963889-128825-1-git-send-email-bianpan2016@163.... Fixes: a1185ffa2fc ("HFS rewrite") Signed-off-by: Pan Bian bianpan2016@163.com Reviewed-by: Andrew Morton akpm@linux-foundation.org Cc: Joe Perches joe@perches.com Cc: Ernesto A. Fernandez ernesto.mnd.fernandez@gmail.com Cc: Viacheslav Dubeyko slava@dubeyko.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- fs/hfs/btree.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/fs/hfs/btree.c b/fs/hfs/btree.c index 1ab19e660e69..1ff5774a5382 100644 --- a/fs/hfs/btree.c +++ b/fs/hfs/btree.c @@ -328,13 +328,14 @@ void hfs_bmap_free(struct hfs_bnode *node)
nidx -= len * 8; i = node->next; - hfs_bnode_put(node); if (!i) { /* panic */; pr_crit("unable to free bnode %u. bmap not found!\n", node->this); + hfs_bnode_put(node); return; } + hfs_bnode_put(node); node = hfs_bnode_find(tree, i); if (IS_ERR(node)) return;