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. Reported-by: Igor Zhbanov <[email protected]> Signed-off-by: Serge E. Hallyn <[email protected]> Cc: [email protected] --- include/linux/capability.h | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff -Nrup linux-2.4.37/include/linux/capability.h linux-2.4.37.new/include/linux/capability.h --- linux-2.4.37/include/linux/capability.h 2008-12-02 02:01:34.000000000 -0600 +++ linux-2.4.37.new/include/linux/capability.h 2009-03-25 11:09:47.000000000 -0500 @@ -99,10 +99,6 @@ typedef __u32 kernel_cap_t; #define CAP_FSETID 4 -/* Used to decide between falling back on the old suser() or fsuser(). */ - -#define CAP_FS_MASK 0x1f - /* Overrides the restriction that the real or effective user ID of a process sending a signal must match the real or effective user ID of the process receiving the signal. */ @@ -301,6 +297,16 @@ extern kernel_cap_t cap_bset; #endif +/* Used to decide between falling back on the old suser() or fsuser(). */ + +#define CAP_FS_MASK (CAP_TO_MASK(CAP_CHOWN) \ + | CAP_TO_MASK(CAP_DAC_OVERRIDE) \ + | CAP_TO_MASK(CAP_DAC_READ_SEARCH) \ + | CAP_TO_MASK(CAP_FOWNER) \ + | CAP_TO_MASK(CAP_FSETID) \ + | CAP_TO_MASK(CAP_LINUX_IMMUTABLE) \ + | CAP_TO_MASK(CAP_MKNOD)) + #define CAP_EMPTY_SET to_cap_t(0) #define CAP_FULL_SET to_cap_t(~0) #define CAP_INIT_EFF_SET to_cap_t(~0 & ~CAP_TO_MASK(CAP_SETPCAP)) -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
