Kavana Ravindra <kavana.c.ravindra@xxxxxxxxx> wrote: > unreferenced object 0xffff9643edb89900 (size 256): > comm "sd-resolve", pid 220, jiffies 4295016710 (age 208.256s) > hex dump (first 32 bytes): > 01 00 00 00 00 00 00 00 03 00 74 f3 ba b1 b6 b5 ..........t..... > 65 3e 00 00 00 00 00 00 90 f9 a0 ed 43 96 ff ff e>..........C... > backtrace: > [<0000000070d5b185>] kmem_cache_alloc+0x146/0x200 > [<0000000007a27faa>] __nf_conntrack_alloc.isra.13+0x4d/0x170 [nf_conntrack] > [<00000000ecc5b0ec>] init_conntrack+0x6a/0x2f0 [nf_conntrack] > [<000000003d38809f>] nf_conntrack_in+0x2c5/0x360 [nf_conntrack] > [<000000001fe154e3>] ipv4_conntrack_local+0x5d/0x70 [nf_conntrack_ipv4] > [<0000000027adadb2>] nf_hook_slow+0x48/0xd0 > [<000000009893511f>] __ip_local_out+0xbd/0xf0 > [<00000000d68cbd2f>] ip_local_out+0x1c/0x50 > [<00000000995e2f37>] ip_send_skb+0x19/0x40 > [<000000003d95f220>] udp_send_skb.isra.5+0x157/0x360 > [<00000000ebc25968>] udp_sendmsg+0x9d8/0xc10 > [<000000003bef56ec>] inet_sendmsg+0x3e/0xf0 > [<000000008d23e405>] sock_sendmsg+0x1d/0x30 > [<000000008c297097>] ___sys_sendmsg+0x108/0x2b0 > [<00000000f15a806c>] __sys_sendmmsg+0xba/0x1c0 > [<00000000e195d2cf>] __x64_sys_sendmmsg+0x24/0x30 > > In __nf_conntrack_confirm, object ct can be referenced to by the stack variable > ct and the members of ct->tuplehash. kmemleak needs at least one of them to find > the ct object during scan. > > When the ct object is moved from the unconfirmed hlist to the confirmed hlist. > kmemleak cannot see ct object if things happen in the following order and thus > give the above false positive report. > 1) The ct object is removed from the unconfirmed hlist. > 2) kmemleak scans data/bss sections(heap scan passes without heap reference). > 3) The ct object is added to confirmed hlist and the variable ct is destroyed as > the function returns. > 4) kmemleak scans task stacks(stack scan passes without stack reference). > > This patch marks ct object as not a leak. Same comment as last time -- can't kmemleak be fixed to require two passes before reporting this as leaked?
