This is good, but may I suggest using __builtin_add_overflow instead? Jonathan
On Wed, Feb 12, 2025, 1:31 AM Gao Xiang <hsiang...@linux.alibaba.com> wrote: > See the original report [1], otherwise len + 1 will be overflowed. > > Note that EROFS archive can record arbitary symlink sizes in principle, > so we don't assume a short number like 4096. > > [1] https://lore.kernel.org/r/20250210164151.GN1233568@bill-the-cat > Fixes: 830613f8f5bb ("fs/erofs: add erofs filesystem support") > Signed-off-by: Gao Xiang <hsiang...@linux.alibaba.com> > --- > fs/erofs/fs.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/fs/erofs/fs.c b/fs/erofs/fs.c > index 7bd2e8fcfc..64a6c8cad8 100644 > --- a/fs/erofs/fs.c > +++ b/fs/erofs/fs.c > @@ -63,6 +63,9 @@ static int erofs_readlink(struct erofs_inode *vi) > char *target; > int err; > > + if (len >= SIZE_MAX) > + return -EFSCORRUPTED; > + > target = malloc(len + 1); > if (!target) > return -ENOMEM; > -- > 2.43.5 > >
