diff options
Diffstat (limited to 'trunk/2.6.18/30028_random-bound-check-ordering.patch')
| -rw-r--r-- | trunk/2.6.18/30028_random-bound-check-ordering.patch | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/trunk/2.6.18/30028_random-bound-check-ordering.patch b/trunk/2.6.18/30028_random-bound-check-ordering.patch new file mode 100644 index 0000000..f2e9ab5 --- /dev/null +++ b/trunk/2.6.18/30028_random-bound-check-ordering.patch @@ -0,0 +1,42 @@ +From: Matt Mackall <mpm@selenic.com> +Date: Thu, 19 Jul 2007 18:30:14 +0000 (-0700) +Subject: random: fix bound check ordering (CVE-2007-3105) +X-Git-Tag: v2.6.23-rc1~259 +X-Git-Url: http://git.kernel.org/?p=linux%2Fkernel%2Fgit%2Ftorvalds%2Flinux-2.6.git;a=commitdiff_plain;h=5a021e9ffd56c22700133ebc37d607f95be8f7bd + +random: fix bound check ordering (CVE-2007-3105) + +If root raised the default wakeup threshold over the size of the +output pool, the pool transfer function could overflow the stack with +RNG bytes, causing a DoS or potential privilege escalation. + +(Bug reported by the PaX Team <pageexec@freemail.hu>) + +Cc: Theodore Tso <tytso@mit.edu> +Cc: Willy Tarreau <w@1wt.eu> +Signed-off-by: Matt Mackall <mpm@selenic.com> +Signed-off-by: Chris Wright <chrisw@sous-sol.org> +Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> +--- + +diff --git a/drivers/char/random.c b/drivers/char/random.c +index 7f52712..397c714 100644 +--- a/drivers/char/random.c ++++ b/drivers/char/random.c +@@ -693,9 +693,14 @@ static void xfer_secondary_pool(struct entropy_store *r, size_t nbytes) + + if (r->pull && r->entropy_count < nbytes * 8 && + r->entropy_count < r->poolinfo->POOLBITS) { +- int bytes = max_t(int, random_read_wakeup_thresh / 8, +- min_t(int, nbytes, sizeof(tmp))); ++ /* If we're limited, always leave two wakeup worth's BITS */ + int rsvd = r->limit ? 0 : random_read_wakeup_thresh/4; ++ int bytes = nbytes; ++ ++ /* pull at least as many as BYTES as wakeup BITS */ ++ bytes = max_t(int, bytes, random_read_wakeup_thresh / 8); ++ /* but never more than the buffer size */ ++ bytes = min_t(int, bytes, sizeof(tmp)); + + DEBUG_ENT("going to reseed %s with %d bits " + "(%d of %d requested)\n", |