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authorVivek Goyal <vgoyal@redhat.com>2016-07-13 18:00:14 +0300
committerMiklos Szeredi <mszeredi@redhat.com>2016-07-29 13:05:24 +0300
commite29841a0ab3d03e77313abd8fb4c16e80fb26e29 (patch)
tree2fa92fa454d171915a7cfa2ee2800703567cffd4
parentd837a49bd57f1ec2f6411efa829fecc34002b110 (diff)
downloadlinux-e29841a0ab3d03e77313abd8fb4c16e80fb26e29.tar.xz
ovl: dilute permission checks on lower only if not special file
Right now if file is on lower/, we remove MAY_WRITE/MAY_APPEND bits from mask as lower/ will never be written and file will be copied up. But this is not true for special files. These files are not copied up and are opened in place. So don't dilute the checks for these types of files. Reported-by: Dan Walsh <dwalsh@redhat.com> Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
-rw-r--r--fs/overlayfs/inode.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index f7caf16f9bec..76cfe9d04e64 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -137,7 +137,7 @@ int ovl_permission(struct inode *inode, int mask)
return err;
old_cred = ovl_override_creds(inode->i_sb);
- if (!is_upper)
+ if (!is_upper && !special_file(realinode->i_mode))
mask &= ~(MAY_WRITE | MAY_APPEND);
err = inode_permission(realinode, mask);
revert_creds(old_cred);