On Sun, 30 Oct 2022 at 00:14, Hawkins Jiawei <yin31149@xxxxxxxxx> 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 > > 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+232ebdbd36706c965ebf@xxxxxxxxxxxxxxxxxxxxxxxxx > > > > 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 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. 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;
