08 Oct, 2016
1 commit
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Current supplementary groups code can massively overallocate memory and
is implemented in a way so that access to individual gid is done via 2D
array.If number of gids is
Cc: Vasily Kulikov
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
16 Apr, 2015
1 commit
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There are a lot of embedded systems that run most or all of their
functionality in init, running as root:root. For these systems,
supporting multiple users is not necessary.This patch adds a new symbol, CONFIG_MULTIUSER, that makes support for
non-root users, non-root groups, and capabilities optional. It is enabled
under CONFIG_EXPERT menu.When this symbol is not defined, UID and GID are zero in any possible case
and processes always have all capabilities.The following syscalls are compiled out: setuid, setregid, setgid,
setreuid, setresuid, getresuid, setresgid, getresgid, setgroups,
getgroups, setfsuid, setfsgid, capget, capset.Also, groups.c is compiled out completely.
In kernel/capability.c, capable function was moved in order to avoid
adding two ifdef blocks.This change saves about 25 KB on a defconfig build. The most minimal
kernels have total text sizes in the high hundreds of kB rather than
low MB. (The 25k goes down a bit with allnoconfig, but not that much.The kernel was booted in Qemu. All the common functionalities work.
Adding users/groups is not possible, failing with -ENOSYS.Bloat-o-meter output:
add/remove: 7/87 grow/shrink: 19/397 up/down: 1675/-26325 (-24650)[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Iulia Manda
Reviewed-by: Josh Triplett
Acked-by: Geert Uytterhoeven
Tested-by: Paul E. McKenney
Reviewed-by: Paul E. McKenney
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
10 Dec, 2014
1 commit
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setgroups is unique in not needing a valid mapping before it can be called,
in the case of setgroups(0, NULL) which drops all supplemental groups.The design of the user namespace assumes that CAP_SETGID can not actually
be used until a gid mapping is established. Therefore add a helper function
to see if the user namespace gid mapping has been established and call
that function in the setgroups permission check.This is part of the fix for CVE-2014-8989, being able to drop groups
without privilege using user namespaces.Cc: stable@vger.kernel.org
Reviewed-by: Andy Lutomirski
Signed-off-by: "Eric W. Biederman"
06 Dec, 2014
1 commit
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Today there are 3 instances of setgroups and due to an oversight their
permission checking has diverged. Add a common function so that
they may all share the same permission checking code.This corrects the current oversight in the current permission checks
and adds a helper to avoid this in the future.A user namespace security fix will update this new helper, shortly.
Cc: stable@vger.kernel.org
Signed-off-by: "Eric W. Biederman"
04 Apr, 2014
1 commit
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After commit 6307f8fee295 ("security: remove dead hook task_setgroups"),
set_groups will always return zero, so we could just remove return value
of set_groups.This patch reduces code size, and simplfies code to use set_groups,
because we don't need to check its return value any more.[akpm@linux-foundation.org: remove obsolete claims from set_groups() comment]
Signed-off-by: Wang YanQing
Cc: "Eric W. Biederman"
Cc: Serge Hallyn
Cc: Eric Paris
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
31 Aug, 2013
1 commit
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nsown_capable is a special case of ns_capable essentially for just CAP_SETUID and
CAP_SETGID. For the existing users it doesn't noticably simplify things and
from the suggested patches I have seen it encourages people to do the wrong
thing. So remove nsown_capable.Acked-by: Serge Hallyn
Signed-off-by: "Eric W. Biederman"
03 May, 2012
2 commits
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Acked-by: Serge Hallyn
Signed-off-by: Eric W. Biederman -
As a first step to converting struct cred to be all kuid_t and kgid_t
values convert the group values stored in group_info to always be
kgid_t values. Unless user namespaces are used this change should
have no effect.Acked-by: Serge Hallyn
Signed-off-by: Eric W. Biederman
31 Oct, 2011
1 commit
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The changed files were only including linux/module.h for the
EXPORT_SYMBOL infrastructure, and nothing else. Revector them
onto the isolated export header for faster compile times.Nothing to see here but a whole lot of instances of:
-#include
+#includeThis commit is only changing the kernel dir; next targets
will probably be mm, fs, the arch dirs, etc.Signed-off-by: Paul Gortmaker
24 Mar, 2011
1 commit
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CAP_IPC_OWNER and CAP_IPC_LOCK can be checked against current_user_ns(),
because the resource comes from current's own ipc namespace.setuid/setgid are to uids in own namespace, so again checks can be against
current_user_ns().Changelog:
Jan 11: Use task_ns_capable() in place of sched_capable().
Jan 11: Use nsown_capable() as suggested by Bastian Blank.
Jan 11: Clarify (hopefully) some logic in futex and sched.c
Feb 15: use ns_capable for ipc, not nsown_capable
Feb 23: let copy_ipcs handle setting ipc_ns->user_ns
Feb 23: pass ns down rather than taking it from current[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Serge E. Hallyn
Acked-by: "Eric W. Biederman"
Acked-by: Daniel Lezcano
Acked-by: David Howells
Cc: James Morris
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
10 Sep, 2010
1 commit
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gid_t is a unsigned int. If group_info contains a gid greater than
MAX_INT, groups_search() function may look on the wrong side of the search
tree.This solves some unfair "permission denied" problems.
Signed-off-by: Jerome Marchand
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
12 Apr, 2010
1 commit
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Unused hook. Remove.
Signed-off-by: Eric Paris
Signed-off-by: James Morris
17 Jun, 2009
1 commit
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Move supplementary groups implementation to kernel/groups.c .
kernel/sys.c already accumulated quite a few random stuff.Do strictly copy/paste + add required headers to compile. Compile-tested
on many configs and archs.Signed-off-by: Alexey Dobriyan
Cc: Ingo Molnar
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds