Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 0ad30b8f authored by Serge E. Hallyn's avatar Serge E. Hallyn Committed by Linus Torvalds
Browse files

add some long-missing capabilities to fs_mask 

When POSIX capabilities were introduced during the 2.1 Linux
cycle, the fs mask, which represents the capabilities which having
fsuid==0 is supposed to grant, did not include CAP_MKNOD and
CAP_LINUX_IMMUTABLE.  However, before capabilities the privilege
to call these did in fact depend upon fsuid==0.

This patch introduces those capabilities into the fsmask,
restoring the old behavior.

See the thread starting at http://lkml.org/lkml/2009/3/11/157

 for
reference.

Note that if this fix is deemed valid, then earlier kernel versions (2.4
and 2.2) ought to be fixed too.

Changelog:
	[Mar 23] Actually delete old CAP_FS_SET definition...
	[Mar 20] Updated against J. Bruce Fields's patch

Reported-by: default avatarIgor Zhbanov <izh1979@gmail.com>
Signed-off-by: default avatarSerge E. Hallyn <serue@us.ibm.com>
Cc: stable@kernel.org
Cc: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent d3ab02a7

include/linux/capability.h

+19 −4
Original line number Diff line number Diff line
@@ -377,7 +377,21 @@ struct cpu_vfs_cap_data { 
#define CAP_FOR_EACH_U32(__capi)  \

	for (__capi = 0; __capi < _KERNEL_CAPABILITY_U32S; ++__capi)



/*

 * CAP_FS_MASK and CAP_NFSD_MASKS:

 *

 * The fs mask is all the privileges that fsuid==0 historically meant.

 * At one time in the past, that included CAP_MKNOD and CAP_LINUX_IMMUTABLE.

 *

 * It has never meant setting security.* and trusted.* xattrs.

 *

 * We could also define fsmask as follows:

 *   1. CAP_FS_MASK is the privilege to bypass all fs-related DAC permissions

 *   2. The security.* and trusted.* xattrs are fs-related MAC permissions

 */



# define CAP_FS_MASK_B0     (CAP_TO_MASK(CAP_CHOWN)		\

			    | CAP_TO_MASK(CAP_MKNOD)		\

			    | CAP_TO_MASK(CAP_DAC_OVERRIDE)	\

			    | CAP_TO_MASK(CAP_DAC_READ_SEARCH)	\

			    | CAP_TO_MASK(CAP_FOWNER)		\
@@ -392,10 +406,11 @@ struct cpu_vfs_cap_data { 
# define CAP_EMPTY_SET    ((kernel_cap_t){{ 0, 0 }})

# define CAP_FULL_SET     ((kernel_cap_t){{ ~0, ~0 }})

# define CAP_INIT_EFF_SET ((kernel_cap_t){{ ~CAP_TO_MASK(CAP_SETPCAP), ~0 }})

# define CAP_FS_SET       ((kernel_cap_t){{ CAP_FS_MASK_B0, CAP_FS_MASK_B1 } })

# define CAP_FS_SET       ((kernel_cap_t){{ CAP_FS_MASK_B0 \

				    | CAP_TO_MASK(CAP_LINUX_IMMUTABLE), \

				    CAP_FS_MASK_B1 } })

# define CAP_NFSD_SET     ((kernel_cap_t){{ CAP_FS_MASK_B0 \

					    | CAP_TO_MASK(CAP_SYS_RESOURCE) \

					    | CAP_TO_MASK(CAP_MKNOD), \

				    | CAP_TO_MASK(CAP_SYS_RESOURCE), \

				    CAP_FS_MASK_B1 } })



#endif /* _KERNEL_CAPABILITY_U32S != 2 */