Commit Graph

4 Commits

Author SHA1 Message Date
e8d49d1c59 bpf: Annotate data races in bpf_local_storage
[ Upstream commit 0a09a2f933 ]

There are a few cases where hlist_node is checked to be unhashed without
holding the lock protecting its modification. In this case, one must use
hlist_unhashed_lockless to avoid load tearing and KCSAN reports. Fix
this by using lockless variant in places not protected by the lock.

Since this is not prompted by any actual KCSAN reports but only from
code review, I have not included a fixes tag.

Cc: Martin KaFai Lau <martin.lau@kernel.org>
Cc: KP Singh <kpsingh@kernel.org>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20230221200646.2500777-4-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-05-30 12:57:48 +01:00
be006212bd bpf: Do not copy spin lock field from user in bpf_selem_alloc
[ Upstream commit 836e49e103 ]

bpf_selem_alloc function is used by inode_storage, sk_storage and
task_storage maps to set map value, for these map types, there may
be a spin lock in the map value, so if we use memcpy to copy the whole
map value from user, the spin lock field may be initialized incorrectly.

Since the spin lock field is zeroed by kzalloc, call copy_map_value
instead of memcpy to skip copying the spin lock field to fix it.

Fixes: 6ac99e8f23 ("bpf: Introduce bpf sk local storage")
Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Link: https://lore.kernel.org/r/20221114134720.1057939-2-xukuohai@huawei.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-08 11:23:55 +01:00
70b971118e bpf: Use hlist_add_head_rcu when linking to local_storage
The local_storage->list will be traversed by rcu reader in parallel.
Thus, hlist_add_head_rcu() is needed in bpf_selem_link_storage_nolock().
This patch fixes it.

This part of the code has recently been refactored in bpf-next
and this patch makes changes to the new file "bpf_local_storage.c".
Instead of using the original offending commit in the Fixes tag,
the commit that created the file "bpf_local_storage.c" is used.

A separate fix has been provided to the bpf tree.

Fixes: 450af8d0f6 ("bpf: Split bpf_local_storage to bpf_sk_storage")
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20200916204453.2003915-1-kafai@fb.com
2020-09-19 01:12:35 +02:00
450af8d0f6 bpf: Split bpf_local_storage to bpf_sk_storage
A purely mechanical change:

	bpf_sk_storage.c = bpf_sk_storage.c + bpf_local_storage.c
	bpf_sk_storage.h = bpf_sk_storage.h + bpf_local_storage.h

Signed-off-by: KP Singh <kpsingh@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20200825182919.1118197-5-kpsingh@chromium.org
2020-08-25 15:00:04 -07:00