ext4: no need to continue when the number of entries is 1

Fixes: ac27a0e ("[PATCH] ext4: initial copy of files from ext3") Reported-by: [email protected] Closes: https://syzkaller.appspot.com/bug?extid=ae688d469e36fb5138d0 Signed-off-by: Edward Adam Davis <[email protected]> Reported-and-tested-by: [email protected] Link: https://patch.msgid.link/[email protected] Signed-off-by: Theodore Ts'o <[email protected]> Cc: [email protected] CVE-2024-49967 (cherry picked from commit 1a00a39) Signed-off-by: Koichiro Den <[email protected]> Acked-by: Yuxuan Luo <[email protected]> Acked-by: Magali Lemes <[email protected]> Signed-off-by: Stefan Bader <[email protected]>
NVIDIA · Nov 30, 2024 · 7df5984 · 7df5984
1 parent c3825cd
commit 7df5984
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
@@ -2045,7 +2045,7 @@ static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
 		split = count/2;
 
 	hash2 = map[split].hash;
-	continued = hash2 == map[split - 1].hash;
+	continued = split > 0 ? hash2 == map[split - 1].hash : 0;
 	dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
 			(unsigned long)dx_get_block(frame->at),
 					hash2, split, count-split));