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| author | Serge E. Hallyn <serue@us.ibm.com> | 2009-04-13 09:56:14 -0500 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-04-13 08:32:28 -0700 |
| commit | 0ad30b8fd5fe798aae80df6344b415d8309342cc (patch) | |
| tree | a62ffb310ab370df11a8fe2ba2995e952b6522be /include/linux/capability.h | |
| parent | d3ab02a7c51fcbceafe999a515cc8bc4f0d0cfee (diff) | |
| download | lwn-0ad30b8fd5fe798aae80df6344b415d8309342cc.tar.gz lwn-0ad30b8fd5fe798aae80df6344b415d8309342cc.zip | |
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: Igor Zhbanov <izh1979@gmail.com>
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Cc: stable@kernel.org
Cc: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/capability.h')
| -rw-r--r-- | include/linux/capability.h | 23 |
1 files changed, 19 insertions, 4 deletions
diff --git a/include/linux/capability.h b/include/linux/capability.h index 4864a43b2b45..c3021105edc0 100644 --- a/include/linux/capability.h +++ b/include/linux/capability.h @@ -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) \ @@ -392,11 +406,12 @@ 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_FS_MASK_B1 } }) + | CAP_TO_MASK(CAP_SYS_RESOURCE), \ + CAP_FS_MASK_B1 } }) #endif /* _KERNEL_CAPABILITY_U32S != 2 */ |