diff options
| author | Kees Cook <keescook@chromium.org> | 2013-11-05 16:57:35 +1100 |
|---|---|---|
| committer | Stephen Rothwell <sfr@canb.auug.org.au> | 2013-11-05 16:57:35 +1100 |
| commit | 40313cf64fc39f3a209f6889a08cc4cda2032e5d (patch) | |
| tree | ce71e33d0bf778149444c457c0c221ab8bef26f5 /arch | |
| parent | 17e5517a87397bca3525fe085d330c614d076194 (diff) | |
exec/ptrace: fix get_dumpable() incorrect tests
The get_dumpable() return value is not boolean. Most users of the
function actually want to be testing for non-SUID_DUMP_USER(1) rather than
SUID_DUMP_DISABLE(0). The SUID_DUMP_ROOT(2) is also considered a
protected state. Almost all places did this correctly, excepting the two
places fixed in this patch.
Wrong logic:
if (dumpable == SUID_DUMP_DISABLE) { /* be protective */ }
or
if (dumpable == 0) { /* be protective */ }
or
if (!dumpable) { /* be protective */ }
Correct logic:
if (dumpable != SUID_DUMP_USER) { /* be protective */ }
or
if (dumpable != 1) { /* be protective */ }
Without this patch, if the system had set the sysctl fs/suid_dumpable=2, a
user was able to ptrace attach to processes that had dropped privileges to
that user. (This may have been partially mitigated if Yama was enabled.)
The macros have been moved into the file that declares get/set_dumpable(),
which means things like the ia64 code can see them too.
CVE-2013-2929
Reported-by: Vasily Kulikov <segoon@openwall.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/ia64/include/asm/processor.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/ia64/include/asm/processor.h b/arch/ia64/include/asm/processor.h index e0a899a1a8a6..5a84b3a50741 100644 --- a/arch/ia64/include/asm/processor.h +++ b/arch/ia64/include/asm/processor.h @@ -319,7 +319,7 @@ struct thread_struct { regs->loadrs = 0; \ regs->r8 = get_dumpable(current->mm); /* set "don't zap registers" flag */ \ regs->r12 = new_sp - 16; /* allocate 16 byte scratch area */ \ - if (unlikely(!get_dumpable(current->mm))) { \ + if (unlikely(get_dumpable(current->mm) != SUID_DUMP_USER)) { \ /* \ * Zap scratch regs to avoid leaking bits between processes with different \ * uid/privileges. \ |