| Message ID | 20241009060701.2434897-1-mika.westerberg@linux.intel.com |
|---|---|
| State | New |
| Headers | show |
| Series | thunderbolt: Fix KASAN reported stack out-of-bounds read in tb_retimer_scan() | expand |
On Wed, Oct 09, 2024 at 09:07:01AM +0300, Mika Westerberg wrote: > KASAN reported following issue: > > BUG: KASAN: stack-out-of-bounds in tb_retimer_scan+0xffe/0x1550 [thunderbolt] > Read of size 4 at addr ffff88810111fc1c by task kworker/u56:0/11 > CPU: 0 UID: 0 PID: 11 Comm: kworker/u56:0 Tainted: G U 6.11.0+ #1387 > Tainted: [U]=USER > Workqueue: thunderbolt0 tb_handle_hotplug [thunderbolt] > Call Trace: > <TASK> > dump_stack_lvl+0x6c/0x90 > print_report+0xd1/0x630 > kasan_report+0xdb/0x110 > __asan_report_load4_noabort+0x14/0x20 > tb_retimer_scan+0xffe/0x1550 [thunderbolt] > tb_scan_port+0xa6f/0x2060 [thunderbolt] > tb_handle_hotplug+0x17b1/0x3080 [thunderbolt] > process_one_work+0x626/0x1100 > worker_thread+0x6c8/0xfa0 > kthread+0x2c8/0x3a0 > ret_from_fork+0x3a/0x80 > ret_from_fork_asm+0x1a/0x30 > > This happens because the loop variable still gets incremented by one so > max becomes 3 instead of 2, and this makes the second loop read past the > the array declared on the stack. > > Fix this by assigning to max directly in the loop body. > > Fixes: ff6ab055e070 ("thunderbolt: Add receiver lane margining support for retimers") > CC: stable@vger.kernel.org > Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Applied to thunderbolt.git/fixes.
diff --git a/drivers/thunderbolt/retimer.c b/drivers/thunderbolt/retimer.c index 721319329afa..7db9869a9f3f 100644 --- a/drivers/thunderbolt/retimer.c +++ b/drivers/thunderbolt/retimer.c @@ -516,7 +516,7 @@ int tb_retimer_scan(struct tb_port *port, bool add) */ tb_retimer_set_inbound_sbtx(port); - for (i = 1; i <= TB_MAX_RETIMER_INDEX; i++) { + for (max = 1, i = 1; i <= TB_MAX_RETIMER_INDEX; i++) { /* * Last retimer is true only for the last on-board * retimer (the one connected directly to the Type-C @@ -527,9 +527,10 @@ int tb_retimer_scan(struct tb_port *port, bool add) last_idx = i; else if (ret < 0) break; + + max = i; } - max = i; ret = 0; /* Add retimers if they do not exist already */
KASAN reported following issue: BUG: KASAN: stack-out-of-bounds in tb_retimer_scan+0xffe/0x1550 [thunderbolt] Read of size 4 at addr ffff88810111fc1c by task kworker/u56:0/11 CPU: 0 UID: 0 PID: 11 Comm: kworker/u56:0 Tainted: G U 6.11.0+ #1387 Tainted: [U]=USER Workqueue: thunderbolt0 tb_handle_hotplug [thunderbolt] Call Trace: <TASK> dump_stack_lvl+0x6c/0x90 print_report+0xd1/0x630 kasan_report+0xdb/0x110 __asan_report_load4_noabort+0x14/0x20 tb_retimer_scan+0xffe/0x1550 [thunderbolt] tb_scan_port+0xa6f/0x2060 [thunderbolt] tb_handle_hotplug+0x17b1/0x3080 [thunderbolt] process_one_work+0x626/0x1100 worker_thread+0x6c8/0xfa0 kthread+0x2c8/0x3a0 ret_from_fork+0x3a/0x80 ret_from_fork_asm+0x1a/0x30 This happens because the loop variable still gets incremented by one so max becomes 3 instead of 2, and this makes the second loop read past the the array declared on the stack. Fix this by assigning to max directly in the loop body. Fixes: ff6ab055e070 ("thunderbolt: Add receiver lane margining support for retimers") CC: stable@vger.kernel.org Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> --- drivers/thunderbolt/retimer.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)