linux/kernel/bpf
John Fastabend 501ca81760 bpf: sockmap, decrement copied count correctly in redirect error case
Currently, when a redirect occurs in sockmap and an error occurs in
the redirect call we unwind the scatterlist once in the error path
of bpf_tcp_sendmsg_do_redirect() and then again in sendmsg(). Then
in the error path of sendmsg we decrement the copied count by the
send size.

However, its possible we partially sent data before the error was
generated. This can happen if do_tcp_sendpages() partially sends the
scatterlist before encountering a memory pressure error. If this
happens we need to decrement the copied value (the value tracking
how many bytes were actually sent to TCP stack) by the number of
remaining bytes _not_ the entire send size. Otherwise we risk
confusing userspace.

Also we don't need two calls to free the scatterlist one is
good enough. So remove the one in bpf_tcp_sendmsg_do_redirect() and
then properly reduce copied by the number of remaining bytes which
may in fact be the entire send size if no bytes were sent.

To do this use bool to indicate if free_start_sg() should do mem
accounting or not.

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-08-28 09:01:06 +02:00
..
arraymap.c bpf: decouple btf from seq bpf fs dump and enable more maps 2018-08-13 00:52:45 +02:00
bpf_lru_list.c bpf: lru: Lower the PERCPU_NR_SCANS from 16 to 4 2017-04-17 13:55:52 -04:00
bpf_lru_list.h bpf: Only set node->ref = 1 if it has not been set 2017-09-01 09:57:39 -07:00
btf.c bpf: btf: Ensure the member->offset is in the right order 2018-07-24 01:20:44 +02:00
cgroup.c bpf: introduce update_effective_progs() 2018-08-07 14:29:55 +02:00
core.c bpf: fix a rcu usage warning in bpf_prog_array_copy_core() 2018-08-16 21:55:32 +02:00
cpumap.c bpf: fix redirect to map under tail calls 2018-08-17 15:56:23 -07:00
devmap.c bpf: fix redirect to map under tail calls 2018-08-17 15:56:23 -07:00
disasm.c bpf: Remove struct bpf_verifier_env argument from print_bpf_insn 2018-03-23 17:38:57 +01:00
disasm.h bpf: Remove struct bpf_verifier_env argument from print_bpf_insn 2018-03-23 17:38:57 +01:00
hashtab.c bpf: use per htab salt for bucket hash 2018-08-23 18:45:47 +02:00
helpers.c bpf: introduce the bpf_get_local_storage() helper function 2018-08-03 00:47:32 +02:00
inode.c bpf: decouple btf from seq bpf fs dump and enable more maps 2018-08-13 00:52:45 +02:00
local_storage.c bpf: decouple btf from seq bpf fs dump and enable more maps 2018-08-13 00:52:45 +02:00
lpm_trie.c bpf: decouple btf from seq bpf fs dump and enable more maps 2018-08-13 00:52:45 +02:00
Makefile bpf: Introduce BPF_MAP_TYPE_REUSEPORT_SOCKARRAY 2018-08-11 01:58:46 +02:00
map_in_map.c bpf: don't allow create maps of cgroup local storages 2018-08-03 00:47:32 +02:00
map_in_map.h bpf: Add syscall lookup support for fd array and htab 2017-06-29 13:13:25 -04:00
offload.c bpf: offload: allow program and map sharing per-ASIC 2018-07-18 15:10:34 +02:00
percpu_freelist.c bpf: fix lockdep splat 2017-11-15 19:46:32 +09:00
percpu_freelist.h bpf: introduce percpu_freelist 2016-03-08 15:28:31 -05:00
reuseport_array.c bpf: Introduce BPF_MAP_TYPE_REUSEPORT_SOCKARRAY 2018-08-11 01:58:46 +02:00
sockmap.c bpf: sockmap, decrement copied count correctly in redirect error case 2018-08-28 09:01:06 +02:00
stackmap.c bpf: decouple btf from seq bpf fs dump and enable more maps 2018-08-13 00:52:45 +02:00
syscall.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-08-15 15:04:25 -07:00
tnum.c bpf/verifier: improve register value range tracking with ARSH 2018-04-29 08:45:53 -07:00
verifier.c bpf: fix redirect to map under tail calls 2018-08-17 15:56:23 -07:00
xskmap.c bpf: fix redirect to map under tail calls 2018-08-17 15:56:23 -07:00