On Mon, May 24, 2021 at 10:33 AM syzbot <syzbot+e562383183e4b1766930@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > Hello, > > syzbot found the following issue on: > > HEAD commit: c3d0e3fd Merge tag 'fs.idmapped.mount_setattr.v5.13-rc3' o.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=148d0bd7d00000 > kernel config: https://syzkaller.appspot.com/x/.config?x=ae7b129a135ab06b > dashboard link: https://syzkaller.appspot.com/bug?extid=e562383183e4b1766930 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15585a4bd00000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13900753d00000 > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+e562383183e4b1766930@xxxxxxxxxxxxxxxxxxxxxxxxx > > BUG: memory leak > unreferenced object 0xffff888115227800 (size 512): > comm "syz-executor263", pid 8658, jiffies 4294951882 (age 12.560s) > 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: > [<ffffffff83977188>] kmalloc include/linux/slab.h:556 [inline] > [<ffffffff83977188>] kzalloc include/linux/slab.h:686 [inline] > [<ffffffff83977188>] ip_vs_add_service+0x598/0x7c0 net/netfilter/ipvs/ip_vs_ctl.c:1343 > [<ffffffff8397d770>] do_ip_vs_set_ctl+0x810/0xa40 net/netfilter/ipvs/ip_vs_ctl.c:2570 > [<ffffffff838449a8>] nf_setsockopt+0x68/0xa0 net/netfilter/nf_sockopt.c:101 > [<ffffffff839ae4e9>] ip_setsockopt+0x259/0x1ff0 net/ipv4/ip_sockglue.c:1435 > [<ffffffff839fa03c>] raw_setsockopt+0x18c/0x1b0 net/ipv4/raw.c:857 > [<ffffffff83691f20>] __sys_setsockopt+0x1b0/0x360 net/socket.c:2117 > [<ffffffff836920f2>] __do_sys_setsockopt net/socket.c:2128 [inline] > [<ffffffff836920f2>] __se_sys_setsockopt net/socket.c:2125 [inline] > [<ffffffff836920f2>] __x64_sys_setsockopt+0x22/0x30 net/socket.c:2125 > [<ffffffff84350efa>] do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47 > [<ffffffff84400068>] entry_SYSCALL_64_after_hwframe+0x44/0xae do_ip_vs_set_ctl() allows users to add svc with the flags field set. when IP_VS_SVC_F_HASHED is used, and in ip_vs_svc_hash() called ip_vs_add_service() will trigger the err msg: IPVS: ip_vs_svc_hash(): request for already hashed, called from do_ip_vs_set_ctl+0x810/0xa40 and the svc allocated will leak. so fix it by mask the flags with ~IP_VS_SVC_F_HASHED in ip_vs_copy_usvc_compat(), while at it also remove the unnecessary flag IP_VS_SVC_F_HASHED set in ip_vs_edit_service(). diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c index d45dbcba8b49..f09a443c9ec0 100644 --- a/net/netfilter/ipvs/ip_vs_ctl.c +++ b/net/netfilter/ipvs/ip_vs_ctl.c @@ -1497,7 +1497,6 @@ ip_vs_edit_service(struct ip_vs_service *svc, struct ip_vs_service_user_kern *u) /* * Set the flags and timeout value */ - svc->flags = u->flags | IP_VS_SVC_F_HASHED; svc->timeout = u->timeout * HZ; svc->netmask = u->netmask; @@ -2430,7 +2429,7 @@ static void ip_vs_copy_usvc_compat(struct ip_vs_service_user_kern *usvc, /* Deep copy of sched_name is not needed here */ usvc->sched_name = usvc_compat->sched_name; - usvc->flags = usvc_compat->flags; + usvc->flags = usvc_compat->flags & ~IP_VS_SVC_F_HASHED; usvc->timeout = usvc_compat->timeout; usvc->netmask = usvc_compat->netmask; } > > > > --- > 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 syzkaller@xxxxxxxxxxxxxxxx. > > 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
