[bpf,v1,0/2] bpf: fix ktls panic and add tests

Message

Jiayuan Chen Jan. 23, 2025, 5:15 p.m. UTC

We can reproduce the issue using the existing test program:
'test_sockmap --ktls'
Or use the selftest I provided, which will cause a panic:

[ 2172.936997] ------------[ cut here ]------------
[ 2172.936999] kernel BUG at lib/iov_iter.c:629!
......
[ 2172.944996] PKRU: 55555554
[ 2172.945155] Call Trace:
[ 2172.945299]  <TASK>
[ 2172.945428]  ? die+0x36/0x90
[ 2172.945601]  ? do_trap+0xdd/0x100
[ 2172.945795]  ? iov_iter_revert+0x178/0x180
[ 2172.946031]  ? iov_iter_revert+0x178/0x180
[ 2172.946267]  ? do_error_trap+0x7d/0x110
[ 2172.946499]  ? iov_iter_revert+0x178/0x180
[ 2172.946736]  ? exc_invalid_op+0x50/0x70
[ 2172.946961]  ? iov_iter_revert+0x178/0x180
[ 2172.947197]  ? asm_exc_invalid_op+0x1a/0x20
[ 2172.947446]  ? iov_iter_revert+0x178/0x180
[ 2172.947683]  ? iov_iter_revert+0x5c/0x180
[ 2172.947913]  tls_sw_sendmsg_locked.isra.0+0x794/0x840
[ 2172.948206]  tls_sw_sendmsg+0x52/0x80
[ 2172.948420]  ? inet_sendmsg+0x1f/0x70
[ 2172.948634]  __sys_sendto+0x1cd/0x200
[ 2172.948848]  ? find_held_lock+0x2b/0x80
[ 2172.949072]  ? syscall_trace_enter+0x140/0x270
[ 2172.949330]  ? __lock_release.isra.0+0x5e/0x170
[ 2172.949595]  ? find_held_lock+0x2b/0x80
[ 2172.949817]  ? syscall_trace_enter+0x140/0x270
[ 2172.950211]  ? lockdep_hardirqs_on_prepare+0xda/0x190
[ 2172.950632]  ? ktime_get_coarse_real_ts64+0xc2/0xd0
[ 2172.951036]  __x64_sys_sendto+0x24/0x30
[ 2172.951382]  do_syscall_64+0x90/0x170

1. It looks like the issue started occurring after I bounding ktls and bpf
together, and the addition of assertions to iov_iter has caused a panic.
If my fix tag is incorrect, please assist me in correcting the fix tag.

2. I make minimal changes for now, and if there are other reasons that
cause similar panics, we can revisit later. For now, this fix should be
sufficient.

Jiayuan Chen (2):
  bpf: fix ktls panic
  selftests/bpf: add ktls selftest

 net/tls/tls_sw.c                              |   8 +-
 .../selftests/bpf/prog_tests/sockmap_ktls.c   | 175 +++++++++++++++++-
 .../selftests/bpf/progs/test_sockmap_ktls.c   |  26 +++
 3 files changed, 205 insertions(+), 4 deletions(-)
 create mode 100644 tools/testing/selftests/bpf/progs/test_sockmap_ktls.c