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| author | Xin Long <lucien.xin@gmail.com> | 2026-06-15 15:36:30 -0400 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2026-06-17 16:41:34 -0700 |
| commit | 7d8297e26b4e20b5d1c3c3fe51fe81a1c7fbc823 (patch) | |
| tree | 20e17eea32e95e7020d84be745594c8f113de474 /include | |
| parent | aedd02af1f8b0bceb7f42f5a21c41634ca9ed390 (diff) | |
| download | ath-7d8297e26b4e20b5d1c3c3fe51fe81a1c7fbc823.tar.gz | |
sctp: hold socket lock when dumping endpoints in sctp_diag
SCTP_DIAG endpoint dumping was traversing endpoint address lists without
holding lock_sock(), while those lists could change concurrently via
socket operations (e.g., bindx changes). This creates a race where
nla_reserve() counts addresses under RCU protection, but the subsequent
copy may see fewer entries, potentially leaking uninitialized memory to
userspace.
Fix this by:
- Taking a reference on each endpoint during hash traversal
- Moving socket operations (lock_sock()) outside read_lock_bh()
- Serializing address list access during dump
- Reworking sctp_for_each_endpoint() to support restart-based traversal
with (net, pos) tracking
Also:
- Add WARN_ON_ONCE() for inconsistent address counts
- Fix idiag_states filtering for LISTEN vs association cases
- Skip dumping endpoints being freed (ep->base.dead)
- Move dump position tracking into iterator, removing cb->args[4] and
its comment for sctp_ep_dump().,
- Update the comment for cb->args[4] and remove the comment for unused
cb->args[5] for sctp_sock_dump().
Note: traversal is restart-based and may re-scan buckets multiple times,
but this is acceptable due to small bucket sizes and required to support
sleeping-safe callbacks.
This issue was reported by Nico Yip (@_cyeaa_) working with TrendAI Zero
Day Initiative.
Reported-by: Zero Day Initiative <zdi-disclosures@trendmicro.com>
Fixes: 8f840e47f190 ("sctp: add the sctp_diag.c file")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Link: https://patch.msgid.link/4c1b49ab87e0f7d552ebd8172b364b1994e913c9.1781552190.git.lucien.xin@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/net/sctp/sctp.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/include/net/sctp/sctp.h b/include/net/sctp/sctp.h index 60b073fd3ed83..d50c27812504f 100644 --- a/include/net/sctp/sctp.h +++ b/include/net/sctp/sctp.h @@ -111,7 +111,8 @@ int sctp_transport_lookup_process(sctp_callback_t cb, struct net *net, const union sctp_addr *paddr, void *p, int dif); int sctp_transport_traverse_process(sctp_callback_t cb, sctp_callback_t cb_done, struct net *net, int *pos, void *p); -int sctp_for_each_endpoint(int (*cb)(struct sctp_endpoint *, void *), void *p); +int sctp_for_each_endpoint(int (*cb)(struct sctp_endpoint *, void *), + struct net *net, int *pos, void *p); int sctp_get_sctp_info(struct sock *sk, struct sctp_association *asoc, struct sctp_info *info); |