[syzbot] memory leak in regulatory_hint_core

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: aae703b02f92 Merge tag 'for-6.1-rc1-tag' of git://git.kern..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=113ed1b4880000
kernel config: https://syzkaller.appspot.com/x/.config?x=d2f454d7d3b63980
dashboard link: https://syzkaller.appspot.com/bug?extid=232ebdbd36706c965ebf
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=124b8de2880000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12ae6a4a880000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/a6542869e73f/disk-aae703b0.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/1a8ac40b2df8/vmlinux-aae703b0.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+232ebd...@syzkaller.appspotmail.com

executing program
BUG: memory leak
unreferenced object 0xffff8881450a3900 (size 64):
comm "swapper/0", pid 1, jiffies 4294937964 (age 66.260s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
ff ff ff ff 00 00 00 00 00 00 00 00 30 30 00 00 ............00..
backtrace:
[<ffffffff814cf9f0>] kmalloc_trace+0x20/0x90 mm/slab_common.c:1046
[<ffffffff84070f62>] kmalloc include/linux/slab.h:576 [inline]
[<ffffffff84070f62>] kzalloc include/linux/slab.h:712 [inline]
[<ffffffff84070f62>] regulatory_hint_core+0x22/0x60 net/wireless/reg.c:3242
[<ffffffff8722bfc1>] regulatory_init_db+0x222/0x2de net/wireless/reg.c:4312
[<ffffffff81000fde>] do_one_initcall+0x5e/0x2e0 init/main.c:1303
[<ffffffff8718db35>] do_initcall_level init/main.c:1376 [inline]
[<ffffffff8718db35>] do_initcalls init/main.c:1392 [inline]
[<ffffffff8718db35>] do_basic_setup init/main.c:1411 [inline]
[<ffffffff8718db35>] kernel_init_freeable+0x255/0x2cf init/main.c:1631
[<ffffffff8460cb9a>] kernel_init+0x1a/0x1c0 init/main.c:1519
[<ffffffff8100224f>] ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306

BUG: memory leak
unreferenced object 0xffff88810c287f00 (size 256):
comm "syz-executor105", pid 3600, jiffies 4294943292 (age 12.990s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffffffff814cf9f0>] kmalloc_trace+0x20/0x90 mm/slab_common.c:1046
[<ffffffff839c9e07>] kmalloc include/linux/slab.h:576 [inline]
[<ffffffff839c9e07>] kmalloc_array include/linux/slab.h:627 [inline]
[<ffffffff839c9e07>] kcalloc include/linux/slab.h:659 [inline]
[<ffffffff839c9e07>] tcf_exts_init include/net/pkt_cls.h:250 [inline]
[<ffffffff839c9e07>] tcindex_set_parms+0xa7/0xbe0 net/sched/cls_tcindex.c:342
[<ffffffff839caa1f>] tcindex_change+0xdf/0x120 net/sched/cls_tcindex.c:553
[<ffffffff8394db62>] tc_new_tfilter+0x4f2/0x1100 net/sched/cls_api.c:2147
[<ffffffff8389e91c>] rtnetlink_rcv_msg+0x4dc/0x5d0 net/core/rtnetlink.c:6082
[<ffffffff839eba67>] netlink_rcv_skb+0x87/0x1d0 net/netlink/af_netlink.c:2540
[<ffffffff839eab87>] netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
[<ffffffff839eab87>] netlink_unicast+0x397/0x4c0 net/netlink/af_netlink.c:1345
[<ffffffff839eb046>] netlink_sendmsg+0x396/0x710 net/netlink/af_netlink.c:1921
[<ffffffff8383e796>] sock_sendmsg_nosec net/socket.c:714 [inline]
[<ffffffff8383e796>] sock_sendmsg+0x56/0x80 net/socket.c:734
[<ffffffff8383eb08>] ____sys_sendmsg+0x178/0x410 net/socket.c:2482
[<ffffffff83843678>] ___sys_sendmsg+0xa8/0x110 net/socket.c:2536
[<ffffffff838439c5>] __sys_sendmmsg+0x105/0x330 net/socket.c:2622
[<ffffffff83843c14>] __do_sys_sendmmsg net/socket.c:2651 [inline]
[<ffffffff83843c14>] __se_sys_sendmmsg net/socket.c:2648 [inline]
[<ffffffff83843c14>] __x64_sys_sendmmsg+0x24/0x30 net/socket.c:2648
[<ffffffff84605fd5>] do_syscall_x64 arch/x86/entry/common.c:50 [inline]
[<ffffffff84605fd5>] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
[<ffffffff84800087>] entry_SYSCALL_64_after_hwframe+0x63/0xcd

BUG: memory leak
unreferenced object 0xffff88810c287e00 (size 256):
comm "syz-executor105", pid 3600, jiffies 4294943292 (age 12.990s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffffffff814cf9f0>] kmalloc_trace+0x20/0x90 mm/slab_common.c:1046
[<ffffffff839c9e07>] kmalloc include/linux/slab.h:576 [inline]
[<ffffffff839c9e07>] kmalloc_array include/linux/slab.h:627 [inline]
[<ffffffff839c9e07>] kcalloc include/linux/slab.h:659 [inline]
[<ffffffff839c9e07>] tcf_exts_init include/net/pkt_cls.h:250 [inline]
[<ffffffff839c9e07>] tcindex_set_parms+0xa7/0xbe0 net/sched/cls_tcindex.c:342
[<ffffffff839caa1f>] tcindex_change+0xdf/0x120 net/sched/cls_tcindex.c:553
[<ffffffff8394db62>] tc_new_tfilter+0x4f2/0x1100 net/sched/cls_api.c:2147
[<ffffffff8389e91c>] rtnetlink_rcv_msg+0x4dc/0x5d0 net/core/rtnetlink.c:6082
[<ffffffff839eba67>] netlink_rcv_skb+0x87/0x1d0 net/netlink/af_netlink.c:2540
[<ffffffff839eab87>] netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
[<ffffffff839eab87>] netlink_unicast+0x397/0x4c0 net/netlink/af_netlink.c:1345
[<ffffffff839eb046>] netlink_sendmsg+0x396/0x710 net/netlink/af_netlink.c:1921
[<ffffffff8383e796>] sock_sendmsg_nosec net/socket.c:714 [inline]
[<ffffffff8383e796>] sock_sendmsg+0x56/0x80 net/socket.c:734
[<ffffffff8383eb08>] ____sys_sendmsg+0x178/0x410 net/socket.c:2482
[<ffffffff83843678>] ___sys_sendmsg+0xa8/0x110 net/socket.c:2536
[<ffffffff838439c5>] __sys_sendmmsg+0x105/0x330 net/socket.c:2622
[<ffffffff83843c14>] __do_sys_sendmmsg net/socket.c:2651 [inline]
[<ffffffff83843c14>] __se_sys_sendmmsg net/socket.c:2648 [inline]
[<ffffffff83843c14>] __x64_sys_sendmmsg+0x24/0x30 net/socket.c:2648
[<ffffffff84605fd5>] do_syscall_x64 arch/x86/entry/common.c:50 [inline]
[<ffffffff84605fd5>] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
[<ffffffff84800087>] entry_SYSCALL_64_after_hwframe+0x63/0xcd

BUG: memory leak
unreferenced object 0xffff88810c1c6d00 (size 256):
comm "syz-executor105", pid 3601, jiffies 4294943831 (age 7.600s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffffffff814cf9f0>] kmalloc_trace+0x20/0x90 mm/slab_common.c:1046
[<ffffffff839c9e07>] kmalloc include/linux/slab.h:576 [inline]
[<ffffffff839c9e07>] kmalloc_array include/linux/slab.h:627 [inline]
[<ffffffff839c9e07>] kcalloc include/linux/slab.h:659 [inline]
[<ffffffff839c9e07>] tcf_exts_init include/net/pkt_cls.h:250 [inline]
[<ffffffff839c9e07>] tcindex_set_parms+0xa7/0xbe0 net/sched/cls_tcindex.c:342
[<ffffffff839caa1f>] tcindex_change+0xdf/0x120 net/sched/cls_tcindex.c:553
[<ffffffff8394db62>] tc_new_tfilter+0x4f2/0x1100 net/sched/cls_api.c:2147
[<ffffffff8389e91c>] rtnetlink_rcv_msg+0x4dc/0x5d0 net/core/rtnetlink.c:6082
[<ffffffff839eba67>] netlink_rcv_skb+0x87/0x1d0 net/netlink/af_netlink.c:2540
[<ffffffff839eab87>] netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
[<ffffffff839eab87>] netlink_unicast+0x397/0x4c0 net/netlink/af_netlink.c:1345
[<ffffffff839eb046>] netlink_sendmsg+0x396/0x710 net/netlink/af_netlink.c:1921
[<ffffffff8383e796>] sock_sendmsg_nosec net/socket.c:714 [inline]
[<ffffffff8383e796>] sock_sendmsg+0x56/0x80 net/socket.c:734
[<ffffffff8383eb08>] ____sys_sendmsg+0x178/0x410 net/socket.c:2482
[<ffffffff83843678>] ___sys_sendmsg+0xa8/0x110 net/socket.c:2536
[<ffffffff838439c5>] __sys_sendmmsg+0x105/0x330 net/socket.c:2622
[<ffffffff83843c14>] __do_sys_sendmmsg net/socket.c:2651 [inline]
[<ffffffff83843c14>] __se_sys_sendmmsg net/socket.c:2648 [inline]
[<ffffffff83843c14>] __x64_sys_sendmmsg+0x24/0x30 net/socket.c:2648
[<ffffffff84605fd5>] do_syscall_x64 arch/x86/entry/common.c:50 [inline]
[<ffffffff84605fd5>] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
[<ffffffff84800087>] entry_SYSCALL_64_after_hwframe+0x63/0xcd



---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
syzbot can test patches for this issue, for details see:
https://goo.gl/tpsmEJ#testing-patches

[Hawkins Jiawei]

Hi,

This bug seems to be related to tcindex_set_parms().

To be more specific, kernel should release the old_r->exts before
initializing it. Let us test it.

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
aae703b02f92bde9264366c545e87cec451de471

diff --git a/net/sched/cls_tcindex.c b/net/sched/cls_tcindex.c
index 1c9eeb98d826..00a6c04a4b42 100644
--- a/net/sched/cls_tcindex.c
+++ b/net/sched/cls_tcindex.c
@@ -479,6 +479,7 @@ tcindex_set_parms(struct net *net, struct tcf_proto *tp, unsigned long base,
}

if (old_r && old_r != r) {
+ tcf_exts_destroy(&old_r->exts);
err = tcindex_filter_result_init(old_r, cp, net);
if (err < 0) {
kfree(f);

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
SYZFATAL: executor failed NUM times: executor NUM: exit status NUM

2022/10/30 05:33:05 SYZFATAL: executor failed 11 times: executor 0: exit status 67
SYZFAIL: wrong response packet
(errno 16: Device or resource busy)
loop exited with status 67

SYZFAIL: wrong response packet
(errno 16: Device or resource busy)
loop exited with status 67


Tested on:

commit: aae703b0 Merge tag 'for-6.1-rc1-tag' of git://git.kern..
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=12e3a3e2880000

kernel config: https://syzkaller.appspot.com/x/.config?x=d2f454d7d3b63980
dashboard link: https://syzkaller.appspot.com/bug?extid=232ebdbd36706c965ebf
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

patch: https://syzkaller.appspot.com/x/patch.diff?x=10eb44b6880000

[Hawkins Jiawei]

On Sun, 30 Oct 2022 at 00:14, Hawkins Jiawei <yin3...@gmail.com> wrote:
>
> Hi,
> > Hello,
> >
> > syzbot found the following issue on:
> >
> > HEAD commit: aae703b02f92 Merge tag 'for-6.1-rc1-tag' of git://git.kern..
> > git tree: upstream
> > console output: https://syzkaller.appspot.com/x/log.txt?x=113ed1b4880000

> > kernel config: https://syzkaller.appspot.com/x/.config?x=d2f454d7d3b63980
> > dashboard link: https://syzkaller.appspot.com/bug?extid=232ebdbd36706c965ebf
> > compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

Test if we need to release the old_r->exts after RCU assign.

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
aae703b02f92bde9264366c545e87cec451de471

diff --git a/net/sched/cls_tcindex.c b/net/sched/cls_tcindex.c

index 1c9eeb98d826..1c0bee2544d9 100644
--- a/net/sched/cls_tcindex.c
+++ b/net/sched/cls_tcindex.c
@@ -338,6 +338,9 @@ tcindex_set_parms(struct net *net, struct tcf_proto *tp, unsigned long base,
struct tcf_result cr = {};
int err, balloc = 0;
struct tcf_exts e;
+#ifdef CONFIG_NET_CLS_ACT
+ struct tcf_exts old_e = {};
+#endif

err = tcf_exts_init(&e, net, TCA_TCINDEX_ACT, TCA_TCINDEX_POLICE);
if (err < 0)
@@ -479,6 +482,14 @@ tcindex_set_parms(struct net *net, struct tcf_proto *tp, unsigned long base,

}

if (old_r && old_r != r) {

+#ifdef CONFIG_NET_CLS_ACT
+ /* r->exts is not copied from old_r->exts, and
+ * the following code will clears the old_r, so
+ * we need to destroy it after update the tp->root,
+ * to avoid memory leak bug.
+ */
+ old_e = old_r->exts;
+#endif

err = tcindex_filter_result_init(old_r, cp, net);
if (err < 0) {
kfree(f);

@@ -510,6 +521,9 @@ tcindex_set_parms(struct net *net, struct tcf_proto *tp, unsigned long base,
tcf_exts_destroy(&new_filter_result.exts);
}

+#ifdef CONFIG_NET_CLS_ACT
+ tcf_exts_destroy(&old_e);
+#endif
if (oldp)
tcf_queue_work(&oldp->rwork, tcindex_partial_destroy_work);
return 0;

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-and-tested-by: syzbot+232ebd...@syzkaller.appspotmail.com

Tested on:

commit: aae703b0 Merge tag 'for-6.1-rc1-tag' of git://git.kern..
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git

console output: https://syzkaller.appspot.com/x/log.txt?x=131ffba1880000

kernel config: https://syzkaller.appspot.com/x/.config?x=d2f454d7d3b63980
dashboard link: https://syzkaller.appspot.com/bug?extid=232ebdbd36706c965ebf
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

patch: https://syzkaller.appspot.com/x/patch.diff?x=17589461880000

Note: testing is done by a robot and is best-effort only.

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-and-tested-by: syzbot+232ebd...@syzkaller.appspotmail.com

Tested on:

commit: aae703b0 Merge tag 'for-6.1-rc1-tag' of git://git.kern..
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git

console output: https://syzkaller.appspot.com/x/log.txt?x=1275a615880000

kernel config: https://syzkaller.appspot.com/x/.config?x=d2f454d7d3b63980
dashboard link: https://syzkaller.appspot.com/bug?extid=232ebdbd36706c965ebf
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

patch: https://syzkaller.appspot.com/x/patch.diff?x=12aa2625880000