syzbot reported crash when rawtp program executed through the
test_run interface calls bpf_get_attach_cookie helper or any
other helper that touches task->bpf_ctx pointer.
We need to setup bpf_ctx pointer in rawtp test_run as well,
so fixing this by moving __bpf_trace_run in header file and
using it in test_run callback.
Also renaming __bpf_trace_run to bpf_prog_run_trace.
Fixes: 7adfc6c9b315 ("bpf: Add bpf_get_attach_cookie() BPF helper to access bpf_cookie value")
Reported-by: syzbot+3ab78ff125b7979e45f9@xxxxxxxxxxxxxxxxxxxxxxxxx
Closes: https://syzkaller.appspot.com/bug?extid=3ab78ff125b7979e45f9
Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
---
include/linux/bpf.h | 27 +++++++++++++++++++++++++++
kernel/trace/bpf_trace.c | 28 ++--------------------------
net/bpf/test_run.c | 4 +---
3 files changed, 30 insertions(+), 29 deletions(-)
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 5e694a308081..4eb803b1d308 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -2914,6 +2914,33 @@ static inline void bpf_dynptr_set_rdonly(struct bpf_dynptr_kern *ptr)
}
#endif /* CONFIG_BPF_SYSCALL */
+static __always_inline int
+bpf_prog_run_trace(struct bpf_prog *prog, u64 cookie, u64 *ctx,
+ bpf_prog_run_fn run_prog)
+{
+ struct bpf_run_ctx *old_run_ctx;
+ struct bpf_trace_run_ctx run_ctx;
+ int ret = -1;
+
+ cant_sleep();
+ if (unlikely(this_cpu_inc_return(*(prog->active)) != 1)) {
+ bpf_prog_inc_misses_counter(prog);
+ goto out;
+ }
+
+ run_ctx.bpf_cookie = cookie;
+ old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx);
+
+ rcu_read_lock();
+ ret = run_prog(prog, ctx);
+ rcu_read_unlock();
+
+ bpf_reset_run_ctx(old_run_ctx);
+out:
+ this_cpu_dec(*(prog->active));
+ return ret;
+}
+
static __always_inline int
bpf_probe_read_kernel_common(void *dst, u32 size, const void *unsafe_ptr)
{
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index d1daeab1bbc1..8a23ef42b76b 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -2383,31 +2383,6 @@ void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp)
preempt_enable();
}
-static __always_inline
-void __bpf_trace_run(struct bpf_raw_tp_link *link, u64 *args)
-{
- struct bpf_prog *prog = link->link.prog;
- struct bpf_run_ctx *old_run_ctx;
- struct bpf_trace_run_ctx run_ctx;
-
- cant_sleep();
- if (unlikely(this_cpu_inc_return(*(prog->active)) != 1)) {
- bpf_prog_inc_misses_counter(prog);
- goto out;
- }
-
- run_ctx.bpf_cookie = link->cookie;
- old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx);
-
- rcu_read_lock();
- (void) bpf_prog_run(prog, args);
- rcu_read_unlock();
-
- bpf_reset_run_ctx(old_run_ctx);
-out:
- this_cpu_dec(*(prog->active));
-}
-
#define UNPACK(...) __VA_ARGS__
#define REPEAT_1(FN, DL, X, ...) FN(X)
#define REPEAT_2(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_1(FN, DL, __VA_ARGS__)
@@ -2437,7 +2412,8 @@ void __bpf_trace_run(struct bpf_raw_tp_link *link, u64 *args)
{ \
u64 args[x]; \
REPEAT(x, COPY, __DL_SEM, __SEQ_0_11); \
- __bpf_trace_run(link, args); \
+ (void) bpf_prog_run_trace(link->link.prog, link->cookie,\
+ args, bpf_prog_run); \
} \
EXPORT_SYMBOL_GPL(bpf_trace_run##x)
BPF_TRACE_DEFN_x(1);
diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c
index f6aad4ed2ab2..84d1c91b01ab 100644
--- a/net/bpf/test_run.c
+++ b/net/bpf/test_run.c
@@ -728,9 +728,7 @@ __bpf_prog_test_run_raw_tp(void *data)
{
struct bpf_raw_tp_test_run_info *info = data;
- rcu_read_lock();
- info->retval = bpf_prog_run(info->prog, info->ctx);
- rcu_read_unlock();
+ info->retval = bpf_prog_run_trace(info->prog, 0, info->ctx, bpf_prog_run);
}
int bpf_prog_test_run_raw_tp(struct bpf_prog *prog,
--
2.45.1
