Re: [PATCH] Validate string -> number conversion.

Arkadiusz Miskiewicz
2010-08-25T08:45:22Z

On Wednesday 25 of August 2010, Arkadiusz Miśkiewicz wrote:
> Make sure that numbers passed as string will fit into proper
> types when doing string->uid_t/gid_t/prid_t conversion.
>
> Signed-off-by: Arkadiusz Miśkiewicz <arekm@maven.pl>
> ---
> libxcmd/input.c | 18 +++++++++++++++---
> quota/project.c | 2 +-
> 2 files changed, 16 insertions(+), 4 deletions(-)

On the kernel side something like below is needed (compile tested only).
The true fix is to extend on disk di_projid to 32bit (there is room for that).

diff --git a/fs/xfs/linux-2.6/xfs_ioctl.c b/fs/xfs/linux-2.6/xfs_ioctl.c
index 237f5ff..1d9cf4f 100644
--- a/fs/xfs/linux-2.6/xfs_ioctl.c
+++ b/fs/xfs/linux-2.6/xfs_ioctl.c
@@ -906,6 +906,11 @@ xfs_ioctl_setattr(
if (XFS_FORCED_SHUTDOWN(mp))
return XFS_ERROR(EIO);

+ /* Make sure a userspace passed projid (32bit) will fit on disk (16bit) */
+ if (fa->fsx_projid > (__uint16_t)-1) {
+ code = XFS_ERROR(EINVAL);
+ goto error_return;
+ }
/*
* If disk quotas is on, we make sure that the dquots do exist on disk,
* before we start any other transactions. Trying to do this later

--
Arkadiusz Miśkiewicz PLD/Linux Team
arekm / maven.pl http://ftp.pld-linux.org/