@@ -2819,7 +2819,7 @@ static int f2fs_move_file_range(struct file *file_in, loff_t pos_in,
}
ret = -EINVAL;
- if (pos_in + len > src->i_size || pos_in + len < pos_in)
+ if (pos_in + len > src->i_size || add_would_overflow(pos_in, len))
goto out_unlock;
if (len == 0)
olen = len = src->i_size - pos_in;
@@ -237,7 +237,7 @@ static int f2fs_get_verity_descriptor(struct inode *inode, void *buf,
pos = le64_to_cpu(dloc.pos);
/* Get the descriptor */
- if (pos + size < pos || pos + size > inode->i_sb->s_maxbytes ||
+ if (add_would_overflow(pos, size) || pos + size > inode->i_sb->s_maxbytes ||
pos < f2fs_verity_metadata_pos(inode) || size > INT_MAX) {
f2fs_warn(F2FS_I_SB(inode), "invalid verity xattr");
f2fs_handle_error(F2FS_I_SB(inode),
In an effort to separate intentional arithmetic wrap-around from unexpected wrap-around, we need to refactor places that depend on this kind of math. One of the most common code patterns of this is: VAR + value < VAR Notably, this is considered "undefined behavior" for signed and pointer types, which the kernel works around by using the -fno-strict-overflow option in the build[1] (which used to just be -fwrapv). Regardless, we want to get the kernel source to the position where we can meaningfully instrument arithmetic wrap-around conditions and catch them when they are unexpected, regardless of whether they are signed[2], unsigned[3], or pointer[4] types. Refactor open-coded wrap-around addition test to use add_would_overflow(). This paves the way to enabling the wrap-around sanitizers in the future. Link: https://git.kernel.org/linus/68df3755e383e6fecf2354a67b08f92f18536594 [1] Link: https://github.com/KSPP/linux/issues/26 [2] Link: https://github.com/KSPP/linux/issues/27 [3] Link: https://github.com/KSPP/linux/issues/344 [4] Cc: Jaegeuk Kim <jaegeuk@kernel.org> Cc: Chao Yu <chao@kernel.org> Cc: linux-f2fs-devel@lists.sourceforge.net Signed-off-by: Kees Cook <keescook@chromium.org> --- fs/f2fs/file.c | 2 +- fs/f2fs/verity.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)