diff options
| author | Eric Dumazet <edumazet@google.com> | 2024-05-10 10:29:32 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2024-05-13 23:53:01 +0300 |
| commit | 1af7f88af269c4e06a4dc3bc920ff6cdf7471124 (patch) | |
| tree | e1512b0d3b87964022d45e950827eca7c631ee3b /net | |
| parent | c9f9df3f6347b33ae770747c40bae38836e3658c (diff) | |
| download | linux-1af7f88af269c4e06a4dc3bc920ff6cdf7471124.tar.xz | |
inet: fix inet_fill_ifaddr() flags truncation
I missed that (struct ifaddrmsg)->ifa_flags was only 8bits,
while (struct in_ifaddr)->ifa_flags is 32bits.
Use a temporary 32bit variable as I did in set_ifa_lifetime()
and check_lifetime().
Fixes: 3ddc2231c810 ("inet: annotate data-races around ifa->ifa_flags")
Reported-by: Yu Watanabe <watanabe.yu@gmail.com>
Dianosed-by: Yu Watanabe <watanabe.yu@gmail.com>
Closes: https://github.com/systemd/systemd/pull/32666#issuecomment-2103977928
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Larysa Zaremba <larysa.zaremba@intel.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20240510072932.2678952-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv4/devinet.c | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c index 7a437f0d4190..7e45c34c8340 100644 --- a/net/ipv4/devinet.c +++ b/net/ipv4/devinet.c @@ -1683,6 +1683,7 @@ static int inet_fill_ifaddr(struct sk_buff *skb, const struct in_ifaddr *ifa, struct nlmsghdr *nlh; unsigned long tstamp; u32 preferred, valid; + u32 flags; nlh = nlmsg_put(skb, args->portid, args->seq, args->event, sizeof(*ifm), args->flags); @@ -1692,7 +1693,13 @@ static int inet_fill_ifaddr(struct sk_buff *skb, const struct in_ifaddr *ifa, ifm = nlmsg_data(nlh); ifm->ifa_family = AF_INET; ifm->ifa_prefixlen = ifa->ifa_prefixlen; - ifm->ifa_flags = READ_ONCE(ifa->ifa_flags); + + flags = READ_ONCE(ifa->ifa_flags); + /* Warning : ifm->ifa_flags is an __u8, it holds only 8 bits. + * The 32bit value is given in IFA_FLAGS attribute. + */ + ifm->ifa_flags = (__u8)flags; + ifm->ifa_scope = ifa->ifa_scope; ifm->ifa_index = ifa->ifa_dev->dev->ifindex; @@ -1701,7 +1708,7 @@ static int inet_fill_ifaddr(struct sk_buff *skb, const struct in_ifaddr *ifa, goto nla_put_failure; tstamp = READ_ONCE(ifa->ifa_tstamp); - if (!(ifm->ifa_flags & IFA_F_PERMANENT)) { + if (!(flags & IFA_F_PERMANENT)) { preferred = READ_ONCE(ifa->ifa_preferred_lft); valid = READ_ONCE(ifa->ifa_valid_lft); if (preferred != INFINITY_LIFE_TIME) { @@ -1732,7 +1739,7 @@ static int inet_fill_ifaddr(struct sk_buff *skb, const struct in_ifaddr *ifa, nla_put_string(skb, IFA_LABEL, ifa->ifa_label)) || (ifa->ifa_proto && nla_put_u8(skb, IFA_PROTO, ifa->ifa_proto)) || - nla_put_u32(skb, IFA_FLAGS, ifm->ifa_flags) || + nla_put_u32(skb, IFA_FLAGS, flags) || (ifa->ifa_rt_priority && nla_put_u32(skb, IFA_RT_PRIORITY, ifa->ifa_rt_priority)) || put_cacheinfo(skb, READ_ONCE(ifa->ifa_cstamp), tstamp, |