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authorKees Cook <keescook@chromium.org>2013-02-07 09:44:13 -0800
committerIngo Molnar <mingo@kernel.org>2013-02-07 19:57:44 +0100
commite575a86fdc50d013bf3ad3aa81d9100e8e6cc60d (patch)
tree04caac94b924d2a3a084f348b999f790f625b09f /arch/x86/mm/gup.c
parentbb9b1a834f7a916a65ba64f4812078cfbe2f4fc4 (diff)
x86: Do not leak kernel page mapping locations
Without this patch, it is trivial to determine kernel page mappings by examining the error code reported to dmesg[1]. Instead, declare the entire kernel memory space as a violation of a present page. Additionally, since show_unhandled_signals is enabled by default, switch branch hinting to the more realistic expectation, and unobfuscate the setting of the PF_PROT bit to improve readability. [1] http://vulnfactory.org/blog/2013/02/06/a-linux-memory-trick/ Reported-by: Dan Rosenberg <dan.j.rosenberg@gmail.com> Suggested-by: Brad Spengler <spender@grsecurity.net> Signed-off-by: Kees Cook <keescook@chromium.org> Cc: stable@vger.kernel.org Acked-by: H. Peter Anvin <hpa@zytor.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20130207174413.GA12485@www.outflux.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/mm/gup.c')
0 files changed, 0 insertions, 0 deletions