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authorChristoph Hellwig <hch@lst.de>2020-01-07 15:25:37 -0800
committerDarrick J. Wong <darrick.wong@oracle.com>2020-01-09 10:55:18 -0800
commit953aa9d136f53e226448dbd801a905c28f8071bf (patch)
tree1a5df80de0c912b38da8efc3ddd600e02cf31563
parent5a57c05b56b6eb2b4e3eb2a9f205e39e849325a1 (diff)
downloadlinux-953aa9d136f53e226448dbd801a905c28f8071bf.tar.bz2
xfs: clear kernel only flags in XFS_IOC_ATTRMULTI_BY_HANDLE
Don't allow passing arbitrary flags as they change behavior including memory allocation that the call stack is not prepared for. Fixes: ddbca70cc45c ("xfs: allocate xattr buffer on demand") Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
-rw-r--r--fs/xfs/libxfs/xfs_attr.h7
-rw-r--r--fs/xfs/xfs_ioctl.c2
-rw-r--r--fs/xfs/xfs_ioctl32.c2
3 files changed, 9 insertions, 2 deletions
diff --git a/fs/xfs/libxfs/xfs_attr.h b/fs/xfs/libxfs/xfs_attr.h
index 94badfa1743e..91c2cb14276e 100644
--- a/fs/xfs/libxfs/xfs_attr.h
+++ b/fs/xfs/libxfs/xfs_attr.h
@@ -26,7 +26,7 @@ struct xfs_attr_list_context;
*========================================================================*/
-#define ATTR_DONTFOLLOW 0x0001 /* -- unused, from IRIX -- */
+#define ATTR_DONTFOLLOW 0x0001 /* -- ignored, from IRIX -- */
#define ATTR_ROOT 0x0002 /* use attrs in root (trusted) namespace */
#define ATTR_TRUST 0x0004 /* -- unused, from IRIX -- */
#define ATTR_SECURE 0x0008 /* use attrs in security namespace */
@@ -37,7 +37,10 @@ struct xfs_attr_list_context;
#define ATTR_KERNOVAL 0x2000 /* [kernel] get attr size only, not value */
#define ATTR_INCOMPLETE 0x4000 /* [kernel] return INCOMPLETE attr keys */
-#define ATTR_ALLOC 0x8000 /* allocate xattr buffer on demand */
+#define ATTR_ALLOC 0x8000 /* [kernel] allocate xattr buffer on demand */
+
+#define ATTR_KERNEL_FLAGS \
+ (ATTR_KERNOTIME | ATTR_KERNOVAL | ATTR_INCOMPLETE | ATTR_ALLOC)
#define XFS_ATTR_FLAGS \
{ ATTR_DONTFOLLOW, "DONTFOLLOW" }, \
diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index 7b35d62ede9f..edfbdb8f85e2 100644
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -462,6 +462,8 @@ xfs_attrmulti_by_handle(
error = 0;
for (i = 0; i < am_hreq.opcount; i++) {
+ ops[i].am_flags &= ~ATTR_KERNEL_FLAGS;
+
ops[i].am_error = strncpy_from_user((char *)attr_name,
ops[i].am_attrname, MAXNAMELEN);
if (ops[i].am_error == 0 || ops[i].am_error == MAXNAMELEN)
diff --git a/fs/xfs/xfs_ioctl32.c b/fs/xfs/xfs_ioctl32.c
index a49bd80b2c3b..20b3edc10f48 100644
--- a/fs/xfs/xfs_ioctl32.c
+++ b/fs/xfs/xfs_ioctl32.c
@@ -450,6 +450,8 @@ xfs_compat_attrmulti_by_handle(
error = 0;
for (i = 0; i < am_hreq.opcount; i++) {
+ ops[i].am_flags &= ~ATTR_KERNEL_FLAGS;
+
ops[i].am_error = strncpy_from_user((char *)attr_name,
compat_ptr(ops[i].am_attrname),
MAXNAMELEN);