[PATCH 3.11 207/208] xfs: underflow bug in xfs_attrlist_by_handle()
Luis Henriques
luis.henriques at canonical.com
Thu Dec 19 11:55:05 UTC 2013
3.11.10.2 -stable review patch. If anyone has any objections, please let me know.
------------------
From: Dan Carpenter <dan.carpenter at oracle.com>
commit 31978b5cc66b8ba8a7e8eef60b12395d41b7b890 upstream.
If we allocate less than sizeof(struct attrlist) then we end up
corrupting memory or doing a ZERO_PTR_SIZE dereference.
This can only be triggered with CAP_SYS_ADMIN.
Reported-by: Nico Golde <nico at ngolde.de>
Reported-by: Fabian Yamaguchi <fabs at goesec.de>
Signed-off-by: Dan Carpenter <dan.carpenter at oracle.com>
Reviewed-by: Dave Chinner <dchinner at redhat.com>
Signed-off-by: Ben Myers <bpm at sgi.com>
Cc: Josh Boyer <jwboyer at fedoraproject.org>
Cc: Kees Cook <keescook at google.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
fs/xfs/xfs_ioctl.c | 3 ++-
fs/xfs/xfs_ioctl32.c | 3 ++-
2 files changed, 4 insertions(+), 2 deletions(-)
diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index bccd2a3..e0bf6f9 100644
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -409,7 +409,8 @@ xfs_attrlist_by_handle(
return -XFS_ERROR(EPERM);
if (copy_from_user(&al_hreq, arg, sizeof(xfs_fsop_attrlist_handlereq_t)))
return -XFS_ERROR(EFAULT);
- if (al_hreq.buflen > XATTR_LIST_MAX)
+ if (al_hreq.buflen < sizeof(struct attrlist) ||
+ al_hreq.buflen > XATTR_LIST_MAX)
return -XFS_ERROR(EINVAL);
/*
diff --git a/fs/xfs/xfs_ioctl32.c b/fs/xfs/xfs_ioctl32.c
index c0c6625..68799d7 100644
--- a/fs/xfs/xfs_ioctl32.c
+++ b/fs/xfs/xfs_ioctl32.c
@@ -359,7 +359,8 @@ xfs_compat_attrlist_by_handle(
if (copy_from_user(&al_hreq, arg,
sizeof(compat_xfs_fsop_attrlist_handlereq_t)))
return -XFS_ERROR(EFAULT);
- if (al_hreq.buflen > XATTR_LIST_MAX)
+ if (al_hreq.buflen < sizeof(struct attrlist) ||
+ al_hreq.buflen > XATTR_LIST_MAX)
return -XFS_ERROR(EINVAL);
/*
--
1.8.3.2
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