fuse: add a flag FUSE_OPEN_KILL_SUIDGID for open() request

With FUSE_HANDLE_KILLPRIV_V2 support, server will need to kill suid/sgid/ security.capability on open(O_TRUNC), if server supports FUSE_ATOMIC_O_TRUNC. But server needs to kill suid/sgid only if caller does not have CAP_FSETID. Given server does not have this information, client needs to send this info to server. So add a flag FUSE_OPEN_KILL_SUIDGID to fuse_open_in request which tells server to kill suid/sgid (only if group execute is set). This flag is added to the FUSE_OPEN request, as well as the FUSE_CREATE request if the create was non-exclusive, since that might result in an existing file being opened/truncated.

Vivek Goyal committed 6 years ago

Commit 643a6661 parent 8981bdf3 files · +21 −2Browse files

Showing the changes to include/uapi (1 of 3 files). Show all

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include/uapi/linux/fuse.h+9−2

@@ -178,6 +178,7 @@ · 177 unmodified lines
178	178	*
179	179	* 7.33
180	180	* - add FUSE_HANDLE_KILLPRIV_V2, FUSE_WRITE_KILL_SUIDGID, FATTR_KILL_SUIDGID
	181	+ * - add FUSE_OPEN_KILL_SUIDGID
181	182	*/
182	183
183	184	#ifndef _LINUX_FUSE_H
@@ -444,6 +445,12 @@ struct fuse_file_lock { · 260 unmodified lines
444	445	*/
445	446	#define FUSE_ATTR_SUBMOUNT (1 << 0)
446	447
	448	+/**
	449	+ * Open flags
	450	+ * FUSE_OPEN_KILL_SUIDGID: Kill suid and sgid if executable
	451	+ */
	452	+#define FUSE_OPEN_KILL_SUIDGID (1 << 0)
	453	+
447	454	enum fuse_opcode {
448	455	FUSE_LOOKUP = 1,
449	456	FUSE_FORGET = 2, /* no reply */
@@ -605,14 +612,14 @@ struct fuse_setattr_in { · 155 unmodified lines
605	612
606	613	struct fuse_open_in {
607	614	uint32_t flags;
608		− uint32_t unused;
	615	+ uint32_t open_flags; /* FUSE_OPEN_... */
609	616	};
610	617
611	618	struct fuse_create_in {
612	619	uint32_t flags;
613	620	uint32_t mode;
614	621	uint32_t umask;
615		− uint32_t padding;
	622	+ uint32_t open_flags; /* FUSE_OPEN_... */
616	623	};
617	624
618	625	struct fuse_open_out {