lib/stackdepot: off by one in depot_fetch_stack()

BugLink: https://bugs.launchpad.net/bugs/2060097

[ Upstream commit dc24559472a682eb124e869cb110e7a2fd857322 ]

The stack_pools[] array has DEPOT_MAX_POOLS.  The "pools_num" tracks the
number of pools which are initialized.  See depot_init_pool() for more
details.

If pool_index == pools_num_cached, this will read one element beyond what
we want.  If not all the pools are initialized, then the pool will be
NULL, triggering a WARN(), and if they are all initialized it will read
one element beyond the end of the array.

Link: https://lkml.kernel.org/r/361ac881-60b7-471f-91e5-5bf8fe8042b2@moroto.mountain
Fixes: b29d318858 ("lib/stackdepot: store free stack records in a freelist")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
(cherry picked from commit 7f71a28b0a17ade767c8ff016433d89c4654d305)
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>

This commit is contained in:

Dan Carpenter

2024-02-23 17:20:13 +03:00

committed by

Roxana Nicolescu

parent d15093f77b

commit 0a92590e89

1 changed files with 1 additions and 1 deletions

									
										lib/stackdepot.c
									
		+1
		-1
	
												View File
												
				@@ -490,7 +490,7 @@ static struct stack_record *depot_fetch_stack(depot_stack_handle_t handle)

					lockdep_assert_not_held(&pool_lock);

					if (pool_index > pools_num_cached) {

					if (pool_index >= pools_num_cached) {

						WARN(1, "pool index %d out of bounds (%d) for stack id %08x\n",

						     pool_index, pools_num_cached, handle);

						return NULL;