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| author | Amery Hung <ameryhung@gmail.com> | 2026-07-14 23:40:41 -0700 |
|---|---|---|
| committer | Kumar Kartikeya Dwivedi <memxor@gmail.com> | 2026-07-15 11:00:45 +0200 |
| commit | c28cbef2f8986c392faf6ca94bb2088548ea6964 (patch) | |
| tree | 7677941015855355a5a27f437816a65b7ade8841 /tools/testing | |
| parent | f68df52fbad0928f4686f734827e5fb6b20386ad (diff) | |
| download | linux-stable-c28cbef2f8986c392faf6ca94bb2088548ea6964.tar.gz linux-stable-c28cbef2f8986c392faf6ca94bb2088548ea6964.zip | |
bpf: Remove dynptr check in check_stack_range_initialized()
For a MEM_UNINIT ("raw mode") helper argument,
check_stack_range_initialized() open-coded a scan that rejected any
STACK_DYNPTR slot in the range with "potential write to dynptr". This
duplicated, and was stricter than, the handling that runs when the
buffer is actually marked initialized. check_helper_call() later replays
the write byte by byte via check_mem_access(), which goes through
destroy_if_dynptr_stack_slot(), which rejects overwritting a referenced
dynptr. Therefore drop the redundant scan and rely on check_mem_access().
Signed-off-by: Amery Hung <ameryhung@gmail.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20260715064047.1793790-2-ameryhung@gmail.com
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Diffstat (limited to 'tools/testing')
| -rw-r--r-- | tools/testing/selftests/bpf/progs/dynptr_fail.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/tools/testing/selftests/bpf/progs/dynptr_fail.c b/tools/testing/selftests/bpf/progs/dynptr_fail.c index 344fb2aa0813..94489ac64da8 100644 --- a/tools/testing/selftests/bpf/progs/dynptr_fail.c +++ b/tools/testing/selftests/bpf/progs/dynptr_fail.c @@ -1112,7 +1112,7 @@ int dynptr_overwrite_ref(void *ctx) /* Reject writes to dynptr slot from bpf_dynptr_read */ SEC("?raw_tp") -__failure __msg("potential write to dynptr at off=-16") +__failure __msg("cannot overwrite referenced dynptr") int dynptr_read_into_slot(void *ctx) { union { @@ -1558,7 +1558,7 @@ int BPF_PROG(skb_invalid_ctx_fexit, void *skb) /* Reject writes to dynptr slot for uninit arg */ SEC("?raw_tp") -__failure __msg("potential write to dynptr at off=-16") +__failure __msg("cannot overwrite referenced dynptr") int uninit_write_into_slot(void *ctx) { struct { |