On Mon, Oct 29, 2018 at 2:53 AM Marcelo Ricardo Leitner <marcelo.leitner@xxxxxxxxx> wrote: > > On Sat, Oct 27, 2018 at 02:58:33PM +0900, Xin Long wrote: > > On Sat, Oct 27, 2018 at 1:38 AM syzbot > > <syzbot+5da0d0a72a9e7d791748@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > > > > > Hello, > > > > > > syzbot found the following crash on: > > > > > > HEAD commit: bd6bf7c10484 Merge tag 'pci-v4.20-changes' of git://git.ke.. > > > git tree: upstream > > > console output: https://syzkaller.appspot.com/x/log.txt?x=16fd6bcb400000 > > > kernel config: https://syzkaller.appspot.com/x/.config?x=2dd8629d56664133 > > > dashboard link: https://syzkaller.appspot.com/bug?extid=5da0d0a72a9e7d791748 > > > compiler: gcc (GCC) 8.0.1 20180413 (experimental) > > > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16b3ea33400000 > > > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17f9f1bd400000 > > > > > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > > > Reported-by: syzbot+5da0d0a72a9e7d791748@xxxxxxxxxxxxxxxxxxxxxxxxx > > > > > > ================================================================== > > > BUG: KASAN: slab-out-of-bounds in sctp_getsockopt_pr_streamstatus > > > net/sctp/socket.c:7174 [inline] > > Forgot to change to use "&" in sctp_getsockopt_pr_streamstatus() in > > "sctp: get pr_assoc and pr_stream all status with SCTP_PR_SCTP_ALL instead" > > > > @@ -7158,7 +7158,7 @@ static int > > sctp_getsockopt_pr_streamstatus(struct sock *sk, int len, > > goto out; > > } > > > > - if (policy == SCTP_PR_SCTP_ALL) { > > + if (policy & SCTP_PR_SCTP_ALL) { > > Hmmm. This is trying to avoid the > streamoute->abandoned_unsent[__SCTP_PR_INDEX(policy)] > with possibly large 'policy' as policy may be SCTP_PR_SCTP_ALL | SCTP_PR_SCTP_MASK > > That said, I don't think this is a good fix because the input > parameter was bogus and we would be trying to make some sense out of > it. So I suggest something along these lines: > > diff --git a/net/sctp/socket.c b/net/sctp/socket.c > index fc0386e8ff23..b816956c69f5 100644 > --- a/net/sctp/socket.c > +++ b/net/sctp/socket.c > @@ -7144,6 +7144,8 @@ static int sctp_getsockopt_pr_streamstatus(struct sock *sk, int len, > policy = params.sprstat_policy; > if (!policy || (policy & ~(SCTP_PR_SCTP_MASK | SCTP_PR_SCTP_ALL))) > goto out; > + if (policy & SCTP_PR_SCTP_ALL && policy & ~SCTP_PR_SCTP_ALL) > + goto out; sure, will change to: @@ -7142,7 +7148,8 @@ static int sctp_getsockopt_pr_streamstatus(struct sock *sk, int len, } policy = params.sprstat_policy; - if (!policy || (policy & ~(SCTP_PR_SCTP_MASK | SCTP_PR_SCTP_ALL))) + if (!policy || (policy & ~(SCTP_PR_SCTP_MASK | SCTP_PR_SCTP_ALL)) || + ((policy & SCTP_PR_SCTP_ALL) && (policy & SCTP_PR_SCTP_MASK))) goto out; including the one in sctp_getsockopt_pr_assocstatus(), thanks. > > asoc = sctp_id2assoc(sk, params.sprstat_assoc_id); > if (!asoc || params.sprstat_sid >= asoc->stream.outcnt) > > To bail out if ALL is specificied together with anything else. > (the if condition probably could be optimized somehow) > > > > > > BUG: KASAN: slab-out-of-bounds in sctp_getsockopt+0x7516/0x7cc2 > > > net/sctp/socket.c:7582 > > > Read of size 8 at addr ffff8801d89f0968 by task syz-executor278/5330 > > > > > > CPU: 1 PID: 5330 Comm: syz-executor278 Not tainted 4.19.0+ #303 > > > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > > > Google 01/01/2011 > > > Call Trace: > > > __dump_stack lib/dump_stack.c:77 [inline] > > > dump_stack+0x244/0x39d lib/dump_stack.c:113 > > > print_address_description.cold.7+0x9/0x1ff mm/kasan/report.c:256 > > > kasan_report_error mm/kasan/report.c:354 [inline] > > > kasan_report.cold.8+0x242/0x309 mm/kasan/report.c:412 > > > __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 > > > sctp_getsockopt_pr_streamstatus net/sctp/socket.c:7174 [inline] > > > sctp_getsockopt+0x7516/0x7cc2 net/sctp/socket.c:7582 > > > sock_common_getsockopt+0x9a/0xe0 net/core/sock.c:2937 > > > __sys_getsockopt+0x1ad/0x390 net/socket.c:1939 > > > __do_sys_getsockopt net/socket.c:1950 [inline] > > > __se_sys_getsockopt net/socket.c:1947 [inline] > > > __x64_sys_getsockopt+0xbe/0x150 net/socket.c:1947 > > > do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 > > > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > > RIP: 0033:0x445789 > > > Code: e8 6c b6 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 > > > 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff > > > ff 0f 83 2b 12 fc ff c3 66 2e 0f 1f 84 00 00 00 00 > > > RSP: 002b:00007effdb293db8 EFLAGS: 00000246 ORIG_RAX: 0000000000000037 > > > RAX: ffffffffffffffda RBX: 00000000006dac48 RCX: 0000000000445789 > > > RDX: 0000000000000074 RSI: 0000000000000084 RDI: 0000000000000003 > > > RBP: 00000000006dac40 R08: 0000000020000040 R09: 0000000000000000 > > > R10: 0000000020000080 R11: 0000000000000246 R12: 00000000006dac4c > > > R13: 00007ffcfc408c6f R14: 00007effdb2949c0 R15: 00000000006dad2c > > > > > > Allocated by task 5329: > > > save_stack+0x43/0xd0 mm/kasan/kasan.c:448 > > > set_track mm/kasan/kasan.c:460 [inline] > > > kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:553 > > > kmem_cache_alloc_trace+0x152/0x750 mm/slab.c:3620 > > > kmalloc include/linux/slab.h:513 [inline] > > > kzalloc include/linux/slab.h:707 [inline] > > > sctp_stream_init_ext+0x4f/0xf0 net/sctp/stream.c:237 > > > sctp_sendmsg_to_asoc+0x1308/0x1a20 net/sctp/socket.c:1896 > > > sctp_sendmsg+0x13c2/0x1da0 net/sctp/socket.c:2113 > > > inet_sendmsg+0x1a1/0x690 net/ipv4/af_inet.c:798 > > > sock_sendmsg_nosec net/socket.c:621 [inline] > > > sock_sendmsg+0xd5/0x120 net/socket.c:631 > > > __sys_sendto+0x3d7/0x670 net/socket.c:1788 > > > __do_sys_sendto net/socket.c:1800 [inline] > > > __se_sys_sendto net/socket.c:1796 [inline] > > > __x64_sys_sendto+0xe1/0x1a0 net/socket.c:1796 > > > do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 > > > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > > > > > Freed by task 3223: > > > save_stack+0x43/0xd0 mm/kasan/kasan.c:448 > > > set_track mm/kasan/kasan.c:460 [inline] > > > __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521 > > > kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 > > > __cache_free mm/slab.c:3498 [inline] > > > kfree+0xcf/0x230 mm/slab.c:3813 > > > kzfree+0x28/0x30 mm/slab_common.c:1543 > > > aa_free_file_ctx security/apparmor/include/file.h:76 [inline] > > > apparmor_file_free_security+0x133/0x1a0 security/apparmor/lsm.c:448 > > > security_file_free+0x4a/0x80 security/security.c:900 > > > file_free fs/file_table.c:54 [inline] > > > __fput+0x4e8/0xa30 fs/file_table.c:294 > > > ____fput+0x15/0x20 fs/file_table.c:309 > > > task_work_run+0x1e8/0x2a0 kernel/task_work.c:113 > > > tracehook_notify_resume include/linux/tracehook.h:188 [inline] > > > exit_to_usermode_loop+0x318/0x380 arch/x86/entry/common.c:166 > > > prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] > > > syscall_return_slowpath arch/x86/entry/common.c:268 [inline] > > > do_syscall_64+0x6be/0x820 arch/x86/entry/common.c:293 > > > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > > > > > The buggy address belongs to the object at ffff8801d89f0900 > > > which belongs to the cache kmalloc-96 of size 96 > > > The buggy address is located 8 bytes to the right of > > > 96-byte region [ffff8801d89f0900, ffff8801d89f0960) > > > The buggy address belongs to the page: > > > page:ffffea0007627c00 count:1 mapcount:0 mapping:ffff8801da8004c0 index:0x0 > > > flags: 0x2fffc0000000100(slab) > > > raw: 02fffc0000000100 ffffea0007646748 ffffea0007613488 ffff8801da8004c0 > > > raw: 0000000000000000 ffff8801d89f0000 0000000100000020 0000000000000000 > > > page dumped because: kasan: bad access detected > > > > > > Memory state around the buggy address: > > > ffff8801d89f0800: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc > > > ffff8801d89f0880: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc > > > > ffff8801d89f0900: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc > > > ^ > > > ffff8801d89f0980: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc > > > ffff8801d89f0a00: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc > > > ================================================================== > > > > > > > > > --- > > > This bug 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 bug report. See: > > > https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with > > > syzbot. > > > syzbot can test patches for this bug, for details see: > > > https://goo.gl/tpsmEJ#testing-patches
