ext4: fix potential null pointer dereference in ext4_free_inode

Fix potential null pointer dereferencing problem caused by e43bb4e ("ext4: decrement free clusters/inodes counters when block group declared bad") Reported-by: Dan Carpenter <[email protected]> Signed-off-by: Namjae Jeon <[email protected]> Signed-off-by: Ashish Sangwan <[email protected]> Signed-off-by: Theodore Ts'o <[email protected]> Reviewed-by: Lukas Czerner <[email protected]>
rtvt123 · Jul 12, 2014 · bf40c92 · bf40c92
1 parent 3f1f9b8
commit bf40c92
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
@@ -338,7 +338,7 @@ void ext4_free_inode(handle_t *handle, struct inode *inode)
 			fatal = err;
 	} else {
 		ext4_error(sb, "bit already cleared for inode %lu", ino);
-		if (!EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) {
+		if (gdp && !EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) {
 			int count;
 			count = ext4_free_inodes_count(sb, gdp);
 			percpu_counter_sub(&sbi->s_freeinodes_counter,