| Message ID | tencent_0CCA1979CFA30DC8A5CF8DDC92365DCE5D07@qq.com |
|---|---|
| State | New |
| Headers | show |
| Series | wifi: mac80211: sband's null check should precede params | expand |
On Wed, 2023-11-29 at 13:48 +0800, Edward Adam Davis wrote: > > [Analysis] > When ieee80211_get_link_sband() fails to find a valid sband and first checks > for params in sta_link_apply_parameters(), it will return 0 due to new_link > being 0, which will lead to an incorrect process after sta_apply_parameters(). > > [Fix] > First obtain sband and perform a non null check before checking the params. Not sure I can even disagree with that analysis, it seems right, but ... > + if (!link || !link_sta) > + return -EINVAL; > + > + sband = ieee80211_get_link_sband(link); > + if (!sband) > + return -EINVAL; > + > /* > * If there are no changes, then accept a link that doesn't exist, > * unless it's a new link. There's a comment here which is clearly not true after this change, since you've already returned for !link_sta? johannes
diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c index 606b1b2e4123..8012dcdbcb5f 100644 --- a/net/mac80211/cfg.c +++ b/net/mac80211/cfg.c @@ -1787,6 +1787,13 @@ static int sta_link_apply_parameters(struct ieee80211_local *local, rcu_dereference_protected(sta->link[link_id], lockdep_is_held(&local->hw.wiphy->mtx)); + if (!link || !link_sta) + return -EINVAL; + + sband = ieee80211_get_link_sband(link); + if (!sband) + return -EINVAL; + /* * If there are no changes, then accept a link that doesn't exist, * unless it's a new link. @@ -1799,13 +1806,6 @@ static int sta_link_apply_parameters(struct ieee80211_local *local, !params->opmode_notif_used) return 0; - if (!link || !link_sta) - return -EINVAL; - - sband = ieee80211_get_link_sband(link); - if (!sband) - return -EINVAL; - if (params->link_mac) { if (new_link) { memcpy(link_sta->addr, params->link_mac, ETH_ALEN);
[Syz report] WARNING: CPU: 1 PID: 5067 at net/mac80211/rate.c:48 rate_control_rate_init+0x540/0x690 net/mac80211/rate.c:48 Modules linked in: CPU: 1 PID: 5067 Comm: syz-executor413 Not tainted 6.7.0-rc3-syzkaller-00014-gdf60cee26a2e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023 RIP: 0010:rate_control_rate_init+0x540/0x690 net/mac80211/rate.c:48 Code: 48 c7 c2 00 46 0c 8c be 08 03 00 00 48 c7 c7 c0 45 0c 8c c6 05 70 79 0b 05 01 e8 1b a0 6f f7 e9 e0 fd ff ff e8 61 b3 8f f7 90 <0f> 0b 90 e9 36 ff ff ff e8 53 b3 8f f7 e8 5e 0b 78 f7 31 ff 89 c3 RSP: 0018:ffffc90003c57248 EFLAGS: 00010293 RAX: 0000000000000000 RBX: ffff888016bc4000 RCX: ffffffff89f7d519 RDX: ffff888076d43b80 RSI: ffffffff89f7d6df RDI: 0000000000000005 RBP: ffff88801daaae20 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000002 R12: 0000000000000001 R13: 0000000000000000 R14: ffff888020030e20 R15: ffff888078f08000 FS: 0000555556b94380(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000005fdeb8 CR3: 0000000076d22000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> sta_apply_auth_flags.constprop.0+0x4b7/0x510 net/mac80211/cfg.c:1674 sta_apply_parameters+0xaf1/0x16c0 net/mac80211/cfg.c:2002 ieee80211_add_station+0x3fa/0x6c0 net/mac80211/cfg.c:2068 rdev_add_station net/wireless/rdev-ops.h:201 [inline] nl80211_new_station+0x13ba/0x1a70 net/wireless/nl80211.c:7603 genl_family_rcv_msg_doit+0x1fc/0x2e0 net/netlink/genetlink.c:972 genl_family_rcv_msg net/netlink/genetlink.c:1052 [inline] genl_rcv_msg+0x561/0x800 net/netlink/genetlink.c:1067 netlink_rcv_skb+0x16b/0x440 net/netlink/af_netlink.c:2545 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1076 netlink_unicast_kernel net/netlink/af_netlink.c:1342 [inline] netlink_unicast+0x53b/0x810 net/netlink/af_netlink.c:1368 netlink_sendmsg+0x93c/0xe40 net/netlink/af_netlink.c:1910 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0xd5/0x180 net/socket.c:745 ____sys_sendmsg+0x6ac/0x940 net/socket.c:2584 ___sys_sendmsg+0x135/0x1d0 net/socket.c:2638 __sys_sendmsg+0x117/0x1e0 net/socket.c:2667 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x40/0x110 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x63/0x6b [Analysis] When ieee80211_get_link_sband() fails to find a valid sband and first checks for params in sta_link_apply_parameters(), it will return 0 due to new_link being 0, which will lead to an incorrect process after sta_apply_parameters(). [Fix] First obtain sband and perform a non null check before checking the params. Fixes: b303835dabe0 ("wifi: mac80211: accept STA changes without link changes") Reported-and-tested-by: syzbot+62d7eef57b09bfebcd84@syzkaller.appspotmail.com Signed-off-by: Edward Adam Davis <eadavis@qq.com> --- net/mac80211/cfg.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-)