lkml.org 
[lkml]   [2023]   [Mar]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Date
Subject[PATCH net v2] ice: fix invalid check for empty list in ice_sched_assoc_vsi_to_agg()
The code implicitly assumes that the list iterator finds a correct
handle. If 'vsi_handle' is not found the 'old_agg_vsi_info' was
pointing to an bogus memory location. For safety a separate list
iterator variable should be used to make the != NULL check on
'old_agg_vsi_info' correct under any circumstances.

Additionally Linus proposed to avoid any use of the list iterator
variable after the loop, in the attempt to move the list iterator
variable declaration into the macro to avoid any potential misuse after
the loop. Using it in a pointer comparison after the loop is undefined
behavior and should be omitted if possible [1].

Fixes: 37c592062b16 ("ice: remove the VSI info from previous agg")
Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ [1]
Signed-off-by: Jakob Koschel <jkl820.git@gmail.com>
---
Changes in v2:
- add Fixes tag
- Link to v1: https://lore.kernel.org/r/20230301-ice-fix-invalid-iterator-found-check-v1-1-87c26deed999@gmail.com
---
drivers/net/ethernet/intel/ice/ice_sched.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_sched.c b/drivers/net/ethernet/intel/ice/ice_sched.c
index 4eca8d195ef0..b7682de0ae05 100644
--- a/drivers/net/ethernet/intel/ice/ice_sched.c
+++ b/drivers/net/ethernet/intel/ice/ice_sched.c
@@ -2788,7 +2788,7 @@ static int
ice_sched_assoc_vsi_to_agg(struct ice_port_info *pi, u32 agg_id,
u16 vsi_handle, unsigned long *tc_bitmap)
{
- struct ice_sched_agg_vsi_info *agg_vsi_info, *old_agg_vsi_info = NULL;
+ struct ice_sched_agg_vsi_info *agg_vsi_info, *iter, *old_agg_vsi_info = NULL;
struct ice_sched_agg_info *agg_info, *old_agg_info;
struct ice_hw *hw = pi->hw;
int status = 0;
@@ -2806,11 +2806,13 @@ ice_sched_assoc_vsi_to_agg(struct ice_port_info *pi, u32 agg_id,
if (old_agg_info && old_agg_info != agg_info) {
struct ice_sched_agg_vsi_info *vtmp;

- list_for_each_entry_safe(old_agg_vsi_info, vtmp,
+ list_for_each_entry_safe(iter, vtmp,
&old_agg_info->agg_vsi_list,
list_entry)
- if (old_agg_vsi_info->vsi_handle == vsi_handle)
+ if (iter->vsi_handle == vsi_handle) {
+ old_agg_vsi_info = iter;
break;
+ }
}

/* check if entry already exist */
---
base-commit: eeac8ede17557680855031c6f305ece2378af326
change-id: 20230301-ice-fix-invalid-iterator-found-check-0a3e5b43dfb3
Best regards,
--
Jakob Koschel <jkl820.git@gmail.com>

\
 
 \ /
  Last update: 2023-03-27 01:09    [W:0.050 / U:2.120 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site