From 04901aab40ea3779f6fc6383ef74d8e130e817bf Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Wed, 30 Dec 2020 21:24:18 -0800 Subject: bpf: Fix a task_iter bug caused by a merge conflict resolution Latest bpf tree has a bug for bpf_iter selftest: $ ./test_progs -n 4/25 test_bpf_sk_storage_get:PASS:bpf_iter_bpf_sk_storage_helpers__open_and_load 0 nsec test_bpf_sk_storage_get:PASS:socket 0 nsec ... do_dummy_read:PASS:read 0 nsec test_bpf_sk_storage_get:FAIL:bpf_map_lookup_elem map value wasn't set correctly (expected 1792, got -1, err=0) #4/25 bpf_sk_storage_get:FAIL #4 bpf_iter:FAIL Summary: 0/0 PASSED, 0 SKIPPED, 2 FAILED When doing merge conflict resolution, Commit 4bfc4714849d missed to save curr_task to seq_file private data. The task pointer in seq_file private data is passed to bpf program. This caused NULL-pointer task passed to bpf program which will immediately return upon checking whether task pointer is NULL. This patch added back the assignment of curr_task to seq_file private data and fixed the issue. Fixes: 4bfc4714849d ("Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf") Signed-off-by: Yonghong Song Signed-off-by: Daniel Borkmann Acked-by: John Fastabend Link: https://lore.kernel.org/bpf/20201231052418.577024-1-yhs@fb.com --- kernel/bpf/task_iter.c | 1 + 1 file changed, 1 insertion(+) (limited to 'kernel/bpf') diff --git a/kernel/bpf/task_iter.c b/kernel/bpf/task_iter.c index 3efe38191d1c..175b7b42bfc4 100644 --- a/kernel/bpf/task_iter.c +++ b/kernel/bpf/task_iter.c @@ -159,6 +159,7 @@ again: } /* set info->task and info->tid */ + info->task = curr_task; if (curr_tid == info->tid) { curr_fd = info->fd; } else { -- cgit v1.2.3