4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Biggers <ebiggers@xxxxxxxxxx> commit e26b6d39270f5eab0087453d9b544189a38c8564 upstream. 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 <ebiggers@xxxxxxxxxx> Reviewed-by: Chao Yu <chao@xxxxxxxxxx> Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/f2fs/xattr.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/fs/f2fs/xattr.c +++ b/fs/f2fs/xattr.c @@ -717,6 +717,12 @@ static int __f2fs_setxattr(struct inode 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);
