From 3179216135ec09825d7c7875580951a6e69dc5df Mon Sep 17 00:00:00 2001 From: Vivek Goyal Date: Fri, 9 Oct 2020 14:15:09 -0400 Subject: fuse: setattr should set FATTR_KILL_SUIDGID If fc->handle_killpriv_v2 is enabled, we expect file server to clear suid/sgid/security.capbility upon chown/truncate/write as appropriate. Upon truncate (ATTR_SIZE), suid/sgid are cleared only if caller does not have CAP_FSETID. File server does not know whether caller has CAP_FSETID or not. Hence set FATTR_KILL_SUIDGID upon truncate to let file server know that caller does not have CAP_FSETID and it should kill suid/sgid as appropriate. On chown (ATTR_UID/ATTR_GID) suid/sgid need to be cleared irrespective of capabilities of calling process, so set FATTR_KILL_SUIDGID unconditionally in that case. Signed-off-by: Vivek Goyal Signed-off-by: Miklos Szeredi --- include/uapi/linux/fuse.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/fuse.h b/include/uapi/linux/fuse.h index 2623c75b94a5..9eb96e0564be 100644 --- a/include/uapi/linux/fuse.h +++ b/include/uapi/linux/fuse.h @@ -177,7 +177,7 @@ * - add flags to fuse_attr, add FUSE_ATTR_SUBMOUNT, add FUSE_SUBMOUNTS * * 7.33 - * - add FUSE_HANDLE_KILLPRIV_V2, FUSE_WRITE_KILL_SUIDGID + * - add FUSE_HANDLE_KILLPRIV_V2, FUSE_WRITE_KILL_SUIDGID, FATTR_KILL_SUIDGID */ #ifndef _LINUX_FUSE_H @@ -274,6 +274,7 @@ struct fuse_file_lock { #define FATTR_MTIME_NOW (1 << 8) #define FATTR_LOCKOWNER (1 << 9) #define FATTR_CTIME (1 << 10) +#define FATTR_KILL_SUIDGID (1 << 11) /** * Flags returned by the OPEN request -- cgit v1.2.3