From: Tom Rix trix@redhat.com
[ Upstream commit 19646447ad3a680d2ab08c097585b7d96a66126b ]
clang static analysis reports this problem
fs/jffs2/summary.c:794:31: warning: Use of memory after it is freed c->summary->sum_list_head = temp->u.next; ^~~~~~~~~~~~
In jffs2_sum_write_data(), in a loop summary data is handles a node at a time. When it has written out the node it is removed the summary list, and the node is deleted. In the corner case when a JFFS2_FEATURE_RWCOMPAT_COPY is seen, a call is made to jffs2_sum_disable_collecting(). jffs2_sum_disable_collecting() deletes the whole list which conflicts with the loop's deleting the list by parts.
To preserve the old behavior of stopping the write midway, bail out of the loop after disabling summary collection.
Fixes: 6171586a7ae5 ("[JFFS2] Correct handling of JFFS2_FEATURE_RWCOMPAT_COPY nodes.") Signed-off-by: Tom Rix trix@redhat.com Reviewed-by: Nathan Chancellor natechancellor@gmail.com Signed-off-by: Richard Weinberger richard@nod.at Signed-off-by: Sasha Levin sashal@kernel.org --- fs/jffs2/summary.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/fs/jffs2/summary.c b/fs/jffs2/summary.c index bc5385471a6e3..c05d6f5f10ecd 100644 --- a/fs/jffs2/summary.c +++ b/fs/jffs2/summary.c @@ -783,6 +783,8 @@ static int jffs2_sum_write_data(struct jffs2_sb_info *c, struct jffs2_eraseblock dbg_summary("Writing unknown RWCOMPAT_COPY node type %x\n", je16_to_cpu(temp->u.nodetype)); jffs2_sum_disable_collecting(c->summary); + /* The above call removes the list, nothing more to do */ + goto bail_rwcompat; } else { BUG(); /* unknown node in summary information */ } @@ -794,6 +796,7 @@ static int jffs2_sum_write_data(struct jffs2_sb_info *c, struct jffs2_eraseblock
c->summary->sum_num--; } + bail_rwcompat:
jffs2_sum_reset_collected(c->summary);