diff mbox series

[net,v4,1/5] ip6mr: Lock RCU before ip6mr_get_table() call in ip6mr_vif_seq_start()

Message ID 20241011074811.2308043-5-stefan.wiehler@nokia.com (mailing list archive)
State New
Delegated to: Netdev Maintainers
Headers show
Series Lock RCU before calling ip6mr_get_table() | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag present in non-next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 5 this patch: 5
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers success CCed 5 of 6 maintainers
netdev/build_clang success Errors and warnings before: 3 this patch: 3
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 6 this patch: 5
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 14 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Stefan Wiehler Oct. 11, 2024, 7:23 a.m. UTC 
When IPV6_MROUTE_MULTIPLE_TABLES is enabled, calls to ip6mr_get_table()
must be done under RCU or RTNL lock.

In case ip6mr_vif_seq_start() fails with an error (currently not
possible, as RT6_TABLE_DFLT always exists, ip6mr_get_table() cannot fail
in this case), ip6mr_vif_seq_stop() would be called and release the RCU
lock.

Signed-off-by: Stefan Wiehler <stefan.wiehler@nokia.com>
Fixes: d1db275dd3f6 ("ipv6: ip6mr: support multiple tables")
Reviewed-by: Eric Dumazet <edumazet@google.com>
---
 net/ipv6/ip6mr.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c
index 2ce4ae0d8dc3..268e77196753 100644
--- a/net/ipv6/ip6mr.c
+++ b/net/ipv6/ip6mr.c
@@ -411,13 +411,13 @@  static void *ip6mr_vif_seq_start(struct seq_file *seq, loff_t *pos)
 	struct net *net = seq_file_net(seq);
 	struct mr_table *mrt;
 
+	rcu_read_lock();
 	mrt = ip6mr_get_table(net, RT6_TABLE_DFLT);
 	if (!mrt)
 		return ERR_PTR(-ENOENT);
 
 	iter->mrt = mrt;
 
-	rcu_read_lock();
 	return mr_vif_seq_start(seq, pos);
 }