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authorKees Cook <kees.cook@canonical.com>2011-03-23 16:42:53 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2011-03-23 19:46:37 -0700
commit5883f57ca0008ffc93e09cbb9847a1928e50c6f3 (patch)
treef7559549b81f1648b089ddfaa202644bf353b3b0 /fs
parent312ec7e50c4d3f40b3762af651d1aa79a67f556a (diff)
proc: protect mm start_code/end_code in /proc/pid/stat
While mm->start_stack was protected from cross-uid viewing (commit f83ce3e6b02d5 ("proc: avoid information leaks to non-privileged processes")), the start_code and end_code values were not. This would allow the text location of a PIE binary to leak, defeating ASLR. Note that the value "1" is used instead of "0" for a protected value since "ps", "killall", and likely other readers of /proc/pid/stat, take start_code of "0" to mean a kernel thread and will misbehave. Thanks to Brad Spengler for pointing this out. Addresses CVE-2011-0726 Signed-off-by: Kees Cook <kees.cook@canonical.com> Cc: <stable@kernel.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: David Howells <dhowells@redhat.com> Cc: Eugene Teo <eugeneteo@kernel.sg> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Brad Spengler <spender@grsecurity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs')
-rw-r--r--fs/proc/array.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/proc/array.c b/fs/proc/array.c
index 7c99c1cf7e5c..5e4f776b0917 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -489,8 +489,8 @@ static int do_task_stat(struct seq_file *m, struct pid_namespace *ns,
vsize,
mm ? get_mm_rss(mm) : 0,
rsslim,
- mm ? mm->start_code : 0,
- mm ? mm->end_code : 0,
+ mm ? (permitted ? mm->start_code : 1) : 0,
+ mm ? (permitted ? mm->end_code : 1) : 0,
(permitted && mm) ? mm->start_stack : 0,
esp,
eip,