This is a note to let you know that I've just added the patch titled
bpftool: Only set obj->skeleton on complete success
to the 5.17-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
bpftool-only-set-obj-skeleton-on-complete-success.patch
and it can be found in the queue-5.17 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 9e00c57fe3afa24541b53defb2e65d7b5d838865
Author: Wei Fu <fuweid89@xxxxxxxxx>
Date: Sat Jan 8 16:40:08 2022 +0800
bpftool: Only set obj->skeleton on complete success
[ Upstream commit 0991f6a38f576aa9a5e34713e23c998a3310d4d0 ]
After `bpftool gen skeleton`, the ${bpf_app}.skel.h will provide that
${bpf_app_name}__open helper to load bpf. If there is some error
like ENOMEM, the ${bpf_app_name}__open will rollback(free) the allocated
object, including `bpf_object_skeleton`.
Since the ${bpf_app_name}__create_skeleton set the obj->skeleton first
and not rollback it when error, it will cause double-free in
${bpf_app_name}__destory at ${bpf_app_name}__open. Therefore, we should
set the obj->skeleton before return 0;
Fixes: 5dc7a8b21144 ("bpftool, selftests/bpf: Embed object file inside skeleton")
Signed-off-by: Wei Fu <fuweid89@xxxxxxxxx>
Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
Link: https://lore.kernel.org/bpf/20220108084008.1053111-1-fuweid89@xxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/tools/bpf/bpftool/gen.c b/tools/bpf/bpftool/gen.c
index b4695df2ea3d..a7387c265e3c 100644
--- a/tools/bpf/bpftool/gen.c
+++ b/tools/bpf/bpftool/gen.c
@@ -927,7 +927,6 @@ static int do_skeleton(int argc, char **argv)
s = (struct bpf_object_skeleton *)calloc(1, sizeof(*s));\n\
if (!s) \n\
goto err; \n\
- obj->skeleton = s; \n\
\n\
s->sz = sizeof(*s); \n\
s->name = \"%1$s\"; \n\
@@ -1000,6 +999,7 @@ static int do_skeleton(int argc, char **argv)
\n\
s->data = (void *)%2$s__elf_bytes(&s->data_sz); \n\
\n\
+ obj->skeleton = s; \n\
return 0; \n\
err: \n\
bpf_object__destroy_skeleton(s); \n\
