| Message ID | 20240329121629.316171-1-artem.chernyshev@red-soft.ru |
|---|---|
| State | New |
| Headers | show |
| Series | fs/jffs2: Fix NULL deref in jffs2_scan_dirty_space | expand |
diff --git a/fs/jffs2/nodelist.c b/fs/jffs2/nodelist.c index b86c78d178c6..6bebf1d64000 100644 --- a/fs/jffs2/nodelist.c +++ b/fs/jffs2/nodelist.c @@ -669,8 +669,11 @@ int jffs2_scan_dirty_space(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb size, jeb->free_size, jeb->wasted_size); BUG(); } + if (!jeb->last_node) { + return -EINVAL; + } /* REF_EMPTY_NODE is !obsolete, so that works OK */ - if (jeb->last_node && ref_obsolete(jeb->last_node)) { + if (ref_obsolete(jeb->last_node) { #ifdef TEST_TOTLEN jeb->last_node->__totlen += size; #endif
As was mentioned in 2ebf09c2, it is possible to get oops, when marking space dirty in scan, but no previous node exists It still can be in jffs2_link_node_ref() via deref jeb->last_node. Since all jffs2_scan_dirty_space() callers check value of a function, we can return error code safely. Found by Linux Verification Center (linuxtesting.org) with SVACE. Signed-off-by: Artem Chernyshev <artem.chernyshev@red-soft.ru> --- fs/jffs2/nodelist.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)