diff mbox series

[net,v2] ipv6: prevent a possible race condition with lifetimes

Message ID 20220223131954.6570-1-niels.dossche@ugent.be (mailing list archive)
State Accepted
Commit 6c0d8833a605e195ae219b5042577ce52bf71fff
Delegated to: Netdev Maintainers
Headers show
Series [net,v2] ipv6: prevent a possible race condition with lifetimes | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net
netdev/fixes_present fail Series targets non-next tree, but doesn't contain any Fixes tags
netdev/subject_prefix success Link
netdev/cover_letter success Single patches do not need cover letters
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/cc_maintainers success CCed 5 of 5 maintainers
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 14 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Niels Dossche Feb. 23, 2022, 1:19 p.m. UTC 
valid_lft, prefered_lft and tstamp are always accessed under the lock
"lock" in other places. Reading these without taking the lock may result
in inconsistencies regarding the calculation of the valid and preferred
variables since decisions are taken on these fields for those variables.

Signed-off-by: Niels Dossche <dossche.niels@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Niels Dossche <niels.dossche@ugent.be>
---
 net/ipv6/addrconf.c | 2 ++
 1 file changed, 2 insertions(+)

Comments

patchwork-bot+netdevbpf@kernel.org Feb. 24, 2022, 5:20 p.m. UTC | #1 
Hello:

This patch was applied to netdev/net.git (master)
by Jakub Kicinski <kuba@kernel.org>:

On Wed, 23 Feb 2022 14:19:56 +0100 you wrote:
> valid_lft, prefered_lft and tstamp are always accessed under the lock
> "lock" in other places. Reading these without taking the lock may result
> in inconsistencies regarding the calculation of the valid and preferred
> variables since decisions are taken on these fields for those variables.
> 
> Signed-off-by: Niels Dossche <dossche.niels@gmail.com>
> Reviewed-by: David Ahern <dsahern@kernel.org>
> Signed-off-by: Niels Dossche <niels.dossche@ugent.be>
> 
> [...]

Here is the summary with links:
  - [net,v2] ipv6: prevent a possible race condition with lifetimes
    https://git.kernel.org/netdev/net/c/6c0d8833a605

You are awesome, thank you!
diff mbox series

Patch

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 3f23da8c0b10..6c8ab3e6e6fe 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -4998,6 +4998,7 @@  static int inet6_fill_ifaddr(struct sk_buff *skb, struct inet6_ifaddr *ifa,
 	    nla_put_s32(skb, IFA_TARGET_NETNSID, args->netnsid))
 		goto error;
 
+	spin_lock_bh(&ifa->lock);
 	if (!((ifa->flags&IFA_F_PERMANENT) &&
 	      (ifa->prefered_lft == INFINITY_LIFE_TIME))) {
 		preferred = ifa->prefered_lft;
@@ -5019,6 +5020,7 @@  static int inet6_fill_ifaddr(struct sk_buff *skb, struct inet6_ifaddr *ifa,
 		preferred = INFINITY_LIFE_TIME;
 		valid = INFINITY_LIFE_TIME;
 	}
+	spin_unlock_bh(&ifa->lock);
 
 	if (!ipv6_addr_any(&ifa->peer_addr)) {
 		if (nla_put_in6_addr(skb, IFA_LOCAL, &ifa->addr) < 0 ||