linux-stable/kernel/events
Ondrej Mosnacek 4348d3b502 perf/core: Fix unconditional security_locked_down() call
commit 08ef1af4de upstream.

Currently, the lockdown state is queried unconditionally, even though
its result is used only if the PERF_SAMPLE_REGS_INTR bit is set in
attr.sample_type. While that doesn't matter in case of the Lockdown LSM,
it causes trouble with the SELinux's lockdown hook implementation.

SELinux implements the locked_down hook with a check whether the current
task's type has the corresponding "lockdown" class permission
("integrity" or "confidentiality") allowed in the policy. This means
that calling the hook when the access control decision would be ignored
generates a bogus permission check and audit record.

Fix this by checking sample_type first and only calling the hook when
its result would be honored.

Fixes: b0c8fdc7fd ("lockdown: Lock down perf when in confidentiality mode")
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Paul Moore <paul@paul-moore.com>
Link: https://lkml.kernel.org/r/20210224215628.192519-1-omosnace@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-07 11:04:33 +02:00
..
callchain.c uaccess: add force_uaccess_{begin,end} helpers 2020-08-12 10:57:59 -07:00
core.c perf/core: Fix unconditional security_locked_down() call 2021-05-07 11:04:33 +02:00
hw_breakpoint.c powerpc/watchpoint: Don't allow concurrent perf and ptrace events 2020-05-19 00:14:45 +10:00
internal.h perf: Optimize get_recursion_context() 2020-11-09 18:12:34 +01:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ring_buffer.c perf: Reduce stack usage of perf_output_begin() 2020-11-09 18:12:33 +01:00
uprobes.c task_work: cleanup notification modes 2020-10-17 15:05:30 -06:00