From: Julia Lawall <julia@xxxxxxx> commit d3533d72e7478a61a3e1936956fc825289a2acf4 upstream (as of v2.6.33-rc3) b_entry_name and buffer are initially NULL, are initialized within a loop to the result of calling kmalloc, and are freed at the bottom of this loop. The loop contains gotos to cleanup, which also frees b_entry_name and buffer. Some of these gotos are before the reinitializations of b_entry_name and buffer. To maintain the invariant that b_entry_name and buffer are NULL at the top of the loop, and thus acceptable arguments to kfree, these variables are now set to NULL after the kfrees. This seems to be the simplest solution. A more complicated solution would be to introduce more labels in the error handling code at the end of the function. A simplified version of the semantic match that finds this problem is as follows: (http://coccinelle.lip6.fr/) // <smpl> @r@ identifier E; expression E1; iterator I; statement S; @@ *kfree(E); ... when != E = E1 when != I(E,...) S when != &E *kfree(E); // </smpl> Signed-off-by: Julia Lawall <julia@xxxxxxx> Signed-off-by: "Theodore Ts'o" <tytso@xxxxxxx> --- fs/ext4/xattr.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c index 0257019..a95769a 100644 --- a/fs/ext4/xattr.c +++ b/fs/ext4/xattr.c @@ -1327,6 +1327,8 @@ retry: goto cleanup; kfree(b_entry_name); kfree(buffer); + b_entry_name = NULL; + buffer = NULL; brelse(is->iloc.bh); kfree(is); kfree(bs); -- 1.6.6.1.1.g974db.dirty -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
