linux-stable.git/include/linux/skbuff.h, branch v6.13.7

net: Implement fault injection forcing skb reallocation

2024-11-12T11:05:33+00:00

Introduce a fault injection mechanism to force skb reallocation. The
primary goal is to catch bugs related to pointer invalidation after
potential skb reallocation.

The fault injection mechanism aims to identify scenarios where callers
retain pointers to various headers in the skb but fail to reload these
pointers after calling a function that may reallocate the data. This
type of bug can lead to memory corruption or crashes if the old,
now-invalid pointers are used.

By forcing reallocation through fault injection, we can stress-test code
paths and ensure proper pointer management after potential skb
reallocations.

Add a hook for fault injection in the following functions:

 * pskb_trim_rcsum()
 * pskb_may_pull_reason()
 * pskb_trim()

As the other fault injection mechanism, protect it under a debug Kconfig
called CONFIG_FAIL_SKB_REALLOC.

This patch was *heavily* inspired by Jakub's proposal from:
https://lore.kernel.org/all/20240719174140.47a868e6@kernel.org/

CC: Akinobu Mita 
Suggested-by: Jakub Kicinski 
Signed-off-by: Breno Leitao 
Reviewed-by: Akinobu Mita 
Acked-by: Paolo Abeni 
Acked-by: Guillaume Nault 
Link: https://patch.msgid.link/20241107-fault_v6-v6-1-1b82cb6ecacd@debian.org
Signed-off-by: Paolo Abeni

mm: move the page fragment allocator from page_alloc into its own file

2024-11-11T18:56:26+00:00

Inspired by [1], move the page fragment allocator from page_alloc
into its own c file and header file, as we are about to make more
change for it to replace another page_frag implementation in
sock.c

As this patchset is going to replace 'struct page_frag' with
'struct page_frag_cache' in sched.h, including page_frag_cache.h
in sched.h has a compiler error caused by interdependence between
mm_types.h and mm.h for asm-offsets.c, see [2]. So avoid the compiler
error by moving 'struct page_frag_cache' to mm_types_task.h as
suggested by Alexander, see [3].

1. https://lore.kernel.org/all/20230411160902.4134381-3-dhowells@redhat.com/
2. https://lore.kernel.org/all/15623dac-9358-4597-b3ee-3694a5956920@gmail.com/
3. https://lore.kernel.org/all/CAKgT0UdH1yD=LSCXFJ=YM_aiA4OomD-2wXykO42bizaWMt_HOA@mail.gmail.com/
CC: David Howells 
CC: Linux-MM 
Signed-off-by: Yunsheng Lin 
Acked-by: Andrew Morton 
Reviewed-by: Alexander Duyck 
Link: https://patch.msgid.link/20241028115343.3405838-3-linyunsheng@huawei.com
Signed-off-by: Jakub Kicinski

net: add debug check in skb_reset_mac_header()

2024-11-07T01:29:15+00:00

Make sure (skb->data - skb->head) can fit in skb->mac_header

This needs CONFIG_DEBUG_NET=y.

Signed-off-by: Eric Dumazet 
Reviewed-by: Joe Damato 
Reviewed-by: Xuan Zhuo 
Link: https://patch.msgid.link/20241105174403.850330-8-edumazet@google.com
Signed-off-by: Jakub Kicinski

net: add debug check in skb_reset_network_header()

2024-11-07T01:29:15+00:00

Make sure (skb->data - skb->head) can fit in skb->network_header

This needs CONFIG_DEBUG_NET=y.

Signed-off-by: Eric Dumazet 
Reviewed-by: Joe Damato 
Reviewed-by: Xuan Zhuo 
Link: https://patch.msgid.link/20241105174403.850330-7-edumazet@google.com
Signed-off-by: Jakub Kicinski

net: add debug check in skb_reset_transport_header()

2024-11-07T01:29:14+00:00

Make sure (skb->data - skb->head) can fit in skb->transport_header

This needs CONFIG_DEBUG_NET=y.

Signed-off-by: Eric Dumazet 
Reviewed-by: Joe Damato 
Reviewed-by: Xuan Zhuo 
Link: https://patch.msgid.link/20241105174403.850330-6-edumazet@google.com
Signed-off-by: Jakub Kicinski

net: add debug check in skb_reset_inner_mac_header()

2024-11-07T01:29:14+00:00

Make sure (skb->data - skb->head) can fit in skb->inner_mac_header

This needs CONFIG_DEBUG_NET=y.

Signed-off-by: Eric Dumazet 
Reviewed-by: Joe Damato 
Reviewed-by: Xuan Zhuo 
Link: https://patch.msgid.link/20241105174403.850330-5-edumazet@google.com
Signed-off-by: Jakub Kicinski

net: add debug check in skb_reset_inner_network_header()

2024-11-07T01:29:14+00:00

Make sure (skb->data - skb->head) can fit in skb->inner_network_header

This needs CONFIG_DEBUG_NET=y.

Signed-off-by: Eric Dumazet 
Reviewed-by: Joe Damato 
Reviewed-by: Xuan Zhuo 
Link: https://patch.msgid.link/20241105174403.850330-4-edumazet@google.com
Signed-off-by: Jakub Kicinski

net: add debug check in skb_reset_inner_transport_header()

2024-11-07T01:29:14+00:00

Make sure (skb->data - skb->head) can fit in skb->inner_transport_header

This needs CONFIG_DEBUG_NET=y.

Signed-off-by: Eric Dumazet 
Reviewed-by: Joe Damato 
Reviewed-by: Xuan Zhuo 
Link: https://patch.msgid.link/20241105174403.850330-3-edumazet@google.com
Signed-off-by: Jakub Kicinski

net: skb_reset_mac_len() must check if mac_header was set

2024-11-07T01:29:14+00:00

Recent discussions show that skb_reset_mac_len() should be more careful.

We expect the MAC header being set.

If not, clear skb->mac_len and fire a warning for CONFIG_DEBUG_NET=y builds.

If after investigations we find that not having a MAC header was okay,
we can remove the warning.

Signed-off-by: Eric Dumazet 
Link: https://lore.kernel.org/netdev/CANn89iJZGH+yEfJxfPWa3Hm7jxb-aeY2Up4HufmLMnVuQXt38A@mail.gmail.com/T/
Cc: En-Wei Wu 
Reviewed-by: Joe Damato 
Reviewed-by: Xuan Zhuo 
Link: https://patch.msgid.link/20241105174403.850330-2-edumazet@google.com
Signed-off-by: Jakub Kicinski

net: skb: add pskb_network_may_pull_reason() helper

2024-10-13T10:33:08+00:00

Introduce the function pskb_network_may_pull_reason() and make
pskb_network_may_pull() a simple inline call to it. The drop reasons of
it just come from pskb_may_pull_reason.

Signed-off-by: Menglong Dong 
Reviewed-by: Simon Horman 
Signed-off-by: David S. Miller