From 086f7316f0d400806d76323beefae996bb3849b1 Mon Sep 17 00:00:00 2001 From: "Andrew G. Morgan" Date: Fri, 4 Jul 2008 09:59:58 -0700 Subject: security: filesystem capabilities: fix fragile setuid fixup code This commit includes a bugfix for the fragile setuid fixup code in the case that filesystem capabilities are supported (in access()). The effect of this fix is gated on filesystem capability support because changing securebits is only supported when filesystem capabilities support is configured.) [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Andrew G. Morgan Acked-by: Serge Hallyn Acked-by: David Howells Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/capability.h | 2 ++ include/linux/securebits.h | 15 ++++++++------- 2 files changed, 10 insertions(+), 7 deletions(-) (limited to 'include') diff --git a/include/linux/capability.h b/include/linux/capability.h index fa830f8de032..02673846d205 100644 --- a/include/linux/capability.h +++ b/include/linux/capability.h @@ -501,6 +501,8 @@ extern const kernel_cap_t __cap_empty_set; extern const kernel_cap_t __cap_full_set; extern const kernel_cap_t __cap_init_eff_set; +kernel_cap_t cap_set_effective(const kernel_cap_t pE_new); + int capable(int cap); int __capable(struct task_struct *t, int cap); diff --git a/include/linux/securebits.h b/include/linux/securebits.h index c1f19dbceb05..92f09bdf1175 100644 --- a/include/linux/securebits.h +++ b/include/linux/securebits.h @@ -7,14 +7,15 @@ inheritance of root-permissions and suid-root executable under compatibility mode. We raise the effective and inheritable bitmasks *of the executable file* if the effective uid of the new process is - 0. If the real uid is 0, we raise the inheritable bitmask of the + 0. If the real uid is 0, we raise the effective (legacy) bit of the executable file. */ #define SECURE_NOROOT 0 #define SECURE_NOROOT_LOCKED 1 /* make bit-0 immutable */ -/* When set, setuid to/from uid 0 does not trigger capability-"fixes" - to be compatible with old programs relying on set*uid to loose - privileges. When unset, setuid doesn't change privileges. */ +/* When set, setuid to/from uid 0 does not trigger capability-"fixup". + When unset, to provide compatiblility with old programs relying on + set*uid to gain/lose privilege, transitions to/from uid 0 cause + capabilities to be gained/lost. */ #define SECURE_NO_SETUID_FIXUP 2 #define SECURE_NO_SETUID_FIXUP_LOCKED 3 /* make bit-2 immutable */ @@ -26,10 +27,10 @@ #define SECURE_KEEP_CAPS 4 #define SECURE_KEEP_CAPS_LOCKED 5 /* make bit-4 immutable */ -/* Each securesetting is implemented using two bits. One bit specify +/* Each securesetting is implemented using two bits. One bit specifies whether the setting is on or off. The other bit specify whether the - setting is fixed or not. A setting which is fixed cannot be changed - from user-level. */ + setting is locked or not. A setting which is locked cannot be + changed from user-level. */ #define issecure_mask(X) (1 << (X)) #define issecure(X) (issecure_mask(X) & current->securebits) -- cgit v1.2.2