On Tue, Aug 18, 2020 at 8:28 AM Stephen Smalley <stephen.smalley.work@xxxxxxxxx> wrote: > > On Mon, Aug 17, 2020 at 10:25 PM Paul Moore <paul@xxxxxxxxxxxxxx> wrote: > > > > On Thu, Aug 13, 2020 at 12:32 PM Stephen Smalley > > <stephen.smalley.work@xxxxxxxxx> wrote: > > > > > > I noticed this in /sys/kernel/debug/kmemleak while testing other > > > patches. This is on 5.8.0-rc1 but may be older. > > > > > > unreferenced object 0xffff888158b40380 (size 32): > > > comm "netlabelctl", pid 2982, jiffies 4295212079 (age 3234.561s) > > > hex dump (first 32 bytes): > > > 80 03 b4 58 81 88 ff ff 80 03 b4 58 81 88 ff ff ...X.......X.... > > > 90 03 b4 58 81 88 ff ff 90 03 b4 58 81 88 ff ff ...X.......X.... > > > backtrace: > > > [<000000009fe161a4>] netlbl_mgmt_add_common+0x2df/0x9b0 > > > [<00000000816cc1d9>] netlbl_mgmt_adddef+0x133/0x190 > > > [<00000000f060e456>] genl_rcv_msg+0x2dd/0x490 > > > [<000000001c733400>] netlink_rcv_skb+0xd0/0x200 > > > [<00000000c42f6f58>] genl_rcv+0x24/0x40 > > > [<000000005421c040>] netlink_unicast+0x2b4/0x3e0 > > > [<00000000ab107bba>] netlink_sendmsg+0x3a6/0x660 > > > [<00000000643024bd>] sock_sendmsg+0x96/0xa0 > > > [<00000000ba78e5a6>] ____sys_sendmsg+0x404/0x440 > > > [<000000006f3de0f5>] ___sys_sendmsg+0xd8/0x140 > > > [<000000009b8c70ea>] __sys_sendmsg+0xa3/0x110 > > > [<00000000e65194c3>] do_syscall_64+0x52/0xb0 > > > [<00000000367aebc6>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > > > Hmmm, that's interesting, a quick look at the code doesn't reveal > > anything obvious and it looks like I don't currently have kmemleak > > enabled in my kernel so I'll need to rebuild ... you wouldn't happen > > to have line numbers for the backtrace above would you? Anything > > special you did to reproduce this? > > I don't still have that kernel so I'll need to reproduce it again. No problem. If you remember to do it next time you've got a test going, it would be nice to have the confirmation, but I started building a kernel this morning (forgot to start it last night). > It > was reproducible however just by running the selinux-testsuite and > then echo scan > /sys/kernel/debug/kmemleak and then cat > /sys/kernel/debug/kmemleak. kmemleak-related config was: > CONFIG_HAVE_DEBUG_KMEMLEAK=y > CONFIG_DEBUG_KMEMLEAK=y > CONFIG_DEBUG_KMEMLEAK_MEM_POOL_SIZE=4096 > # CONFIG_DEBUG_KMEMLEAK_TEST is not set > # CONFIG_DEBUG_KMEMLEAK_DEFAULT_OFF is not set > CONFIG_DEBUG_KMEMLEAK_AUTO_SCAN=y Okay, good. I was worried the reproducer might be tricky, but that's easy enough. -- paul moore www.paul-moore.com
