kernel/linux.git/net/ipv4/ipmr_base.c, branch v6.6.131

ipmr: do not call mr_mfc_uses_dev() for unres entries

2025-02-08T08:52:29+00:00

[ Upstream commit 15a901361ec3fb1c393f91880e1cbf24ec0a88bd ] syzbot found that calling mr_mfc_uses_dev() for unres entries would crash [1], because c->mfc_un.res.minvif / c->mfc_un.res.maxvif alias to "struct sk_buff_head unresolved", which contain two pointers. This code never worked, lets remove it. [1] Unable to handle kernel paging request at virtual address ffff5fff2d536613 KASAN: maybe wild-memory-access in range [0xfffefff96a9b3098-0xfffefff96a9b309f] Modules linked in: CPU: 1 UID: 0 PID: 7321 Comm: syz.0.16 Not tainted 6.13.0-rc7-syzkaller-g1950a0af2d55 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : mr_mfc_uses_dev net/ipv4/ipmr_base.c:290 [inline] pc : mr_table_dump+0x5a4/0x8b0 net/ipv4/ipmr_base.c:334 lr : mr_mfc_uses_dev net/ipv4/ipmr_base.c:289 [inline] lr : mr_table_dump+0x694/0x8b0 net/ipv4/ipmr_base.c:334 Call trace: mr_mfc_uses_dev net/ipv4/ipmr_base.c:290 [inline] (P) mr_table_dump+0x5a4/0x8b0 net/ipv4/ipmr_base.c:334 (P) mr_rtm_dumproute+0x254/0x454 net/ipv4/ipmr_base.c:382 ipmr_rtm_dumproute+0x248/0x4b4 net/ipv4/ipmr.c:2648 rtnl_dump_all+0x2e4/0x4e8 net/core/rtnetlink.c:4327 rtnl_dumpit+0x98/0x1d0 net/core/rtnetlink.c:6791 netlink_dump+0x4f0/0xbc0 net/netlink/af_netlink.c:2317 netlink_recvmsg+0x56c/0xe64 net/netlink/af_netlink.c:1973 sock_recvmsg_nosec net/socket.c:1033 [inline] sock_recvmsg net/socket.c:1055 [inline] sock_read_iter+0x2d8/0x40c net/socket.c:1125 new_sync_read fs/read_write.c:484 [inline] vfs_read+0x740/0x970 fs/read_write.c:565 ksys_read+0x15c/0x26c fs/read_write.c:708 Fixes: cb167893f41e ("net: Plumb support for filtering ipv4 and ipv6 multicast route dumps") Reported-by: syzbot+5cfae50c0e5f2c500013@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/678fe2d1.050a0220.15cac.00b3.GAE@google.com/T/#u Signed-off-by: Eric Dumazet Reviewed-by: David Ahern Link: https://patch.msgid.link/20250121181241.841212-1-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

inet: ipmr: fix data-races

2025-02-08T08:52:02+00:00

[ Upstream commit 3440fa34ad99d471f1085bc2f4dedeaebc310261 ] Following fields of 'struct mr_mfc' can be updated concurrently (no lock protection) from ip_mr_forward() and ip6_mr_forward() - bytes - pkt - wrong_if - lastuse They also can be read from other functions. Convert bytes, pkt and wrong_if to atomic_long_t, and use READ_ONCE()/WRITE_ONCE() for lastuse. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet Reviewed-by: David Ahern Link: https://patch.msgid.link/20250114221049.1190631-1-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

ipmr: Fix access to mfc_cache_list without lock held

2024-12-09T09:31:40+00:00

[ Upstream commit e28acc9c1ccfcb24c08e020828f69d0a915b06ae ] Accessing `mr_table->mfc_cache_list` is protected by an RCU lock. In the following code flow, the RCU read lock is not held, causing the following error when `RCU_PROVE` is not held. The same problem might show up in the IPv6 code path. 6.12.0-rc5-kbuilder-01145-gbac17284bdcb #33 Tainted: G E N ----------------------------- net/ipv4/ipmr_base.c:313 RCU-list traversed in non-reader section!! rcu_scheduler_active = 2, debug_locks = 1 2 locks held by RetransmitAggre/3519: #0: ffff88816188c6c0 (nlk_cb_mutex-ROUTE){+.+.}-{3:3}, at: __netlink_dump_start+0x8a/0x290 #1: ffffffff83fcf7a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_dumpit+0x6b/0x90 stack backtrace: lockdep_rcu_suspicious mr_table_dump ipmr_rtm_dumproute rtnl_dump_all rtnl_dumpit netlink_dump __netlink_dump_start rtnetlink_rcv_msg netlink_rcv_skb netlink_unicast netlink_sendmsg This is not a problem per see, since the RTNL lock is held here, so, it is safe to iterate in the list without the RCU read lock, as suggested by Eric. To alleviate the concern, modify the code to use list_for_each_entry_rcu() with the RTNL-held argument. The annotation will raise an error only if RTNL or RCU read lock are missing during iteration, signaling a legitimate problem, otherwise it will avoid this false positive. This will solve the IPv6 case as well, since ip6mr_rtm_dumproute() calls this function as well. Signed-off-by: Breno Leitao Reviewed-by: David Ahern Link: https://patch.msgid.link/20241108-ipmr_rcu-v2-1-c718998e209b@debian.org Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

ipmr: adopt rcu_read_lock() in mr_dump()

2022-06-24T10:34:38+00:00

We no longer need to acquire mrt_lock() in mr_dump, using rcu_read_lock() is enough. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

ipmr: add rcu protection over (struct vif_device)->dev

2022-06-24T10:34:37+00:00

We will soon use RCU instead of rwlock in ipmr & ip6mr This preliminary patch adds proper rcu verbs to read/write (struct vif_device)->dev Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

net: fib_notifier: propagate extack down to the notifier block callback

2019-10-04T18:10:56+00:00

Since errors are propagated all the way up to the caller, propagate possible extack of the caller all the way down to the notifier block callback. Signed-off-by: Jiri Pirko Signed-off-by: David S. Miller

net: fib_notifier: propagate possible error during fib notifier registration

2019-10-04T18:10:56+00:00

Unlike events for registered notifier, during the registration, the errors that happened for the block being registered are not propagated up to the caller. Make sure the error is propagated for FIB rules and entries. Signed-off-by: Jiri Pirko Signed-off-by: David S. Miller

net: fib_notifier: make FIB notifier per-netns

2019-10-04T18:10:55+00:00

Currently all users of FIB notifier only cares about events in init_net. Later in this patchset, users get interested in other namespaces too. However, for every registered block user is interested only about one namespace. Make the FIB notifier registration per-netns and avoid unnecessary calls of notifier block for other namespaces. Signed-off-by: Jiri Pirko Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2019-05-08T00:22:09+00:00

Minor conflict with the DSA legacy code removal. Signed-off-by: David S. Miller

ipmr_base: Do not reset index in mr_table_dump

2019-05-04T05:38:15+00:00

e is the counter used to save the location of a dump when an skb is filled. Once the walk of the table is complete, mr_table_dump needs to return without resetting that index to 0. Dump of a specific table is looping because of the reset because there is no way to indicate the walk of the table is done. Move the reset to the caller so the dump of each table starts at 0, but the loop counter is maintained if a dump fills an skb. Fixes: e1cedae1ba6b0 ("ipmr: Refactor mr_rtm_dumproute") Signed-off-by: David Ahern Signed-off-by: David S. Miller