From e26b6d39270f5eab0087453d9b544189a38c8564 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Mon, 6 Nov 2023 20:44:34 -0800 Subject: f2fs: explicitly null-terminate the xattr list When setting an xattr, explicitly null-terminate the xattr list. This eliminates the fragile assumption that the unused xattr space is always zeroed. Signed-off-by: Eric Biggers Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim --- fs/f2fs/xattr.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'fs/f2fs') diff --git a/fs/f2fs/xattr.c b/fs/f2fs/xattr.c index 47e88b4d4e7d..a8fc2cac6879 100644 --- a/fs/f2fs/xattr.c +++ b/fs/f2fs/xattr.c @@ -754,6 +754,12 @@ retry: memcpy(pval, value, size); last->e_value_size = cpu_to_le16(size); new_hsize += newsize; + /* + * Explicitly add the null terminator. The unused xattr space + * is supposed to always be zeroed, which would make this + * unnecessary, but don't depend on that. + */ + *(u32 *)((u8 *)last + newsize) = 0; } error = write_all_xattrs(inode, new_hsize, base_addr, ipage); -- cgit