path: root/sysdeps/unix
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authorDaniel Alvarez <dalvarez@redhat.com>2018-06-29 09:44:55 +0200
committerFlorian Weimer <fweimer@redhat.com>2018-06-29 09:44:55 +0200
commitc1f86a33ca32e26a9d6e29fc961e5ecb5e2e5eb4 (patch)
tree2176bd36948fdf0af2387bcc1bc309f896b948c3 /sysdeps/unix
parent0b11b6491cc01b5ce5fea1302f8591f25e8c4d80 (diff)
getifaddrs: Don't return ifa entries with NULL names [BZ #21812]
A lookup operation in map_newlink could turn into an insert because of holes in the interface part of the map. This leads to incorrectly set the name of the interface to NULL when the interface is not present for the address being processed (most likely because the interface was added between the RTM_GETLINK and RTM_GETADDR calls to the kernel). When such changes are detected by the kernel, it'll mark the dump as "inconsistent" by setting NLM_F_DUMP_INTR flag on the next netlink message. This patch checks this condition and retries the whole operation. Hopes are that next time the interface corresponding to the address entry is present in the list and correct name is returned.
Diffstat (limited to 'sysdeps/unix')
1 files changed, 8 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/ifaddrs.c b/sysdeps/unix/sysv/linux/ifaddrs.c
index 32381f54e4..ac0e1e5738 100644
--- a/sysdeps/unix/sysv/linux/ifaddrs.c
+++ b/sysdeps/unix/sysv/linux/ifaddrs.c
@@ -370,6 +370,14 @@ getifaddrs_internal (struct ifaddrs **ifap)
if ((pid_t) nlh->nlmsg_pid != nh.pid || nlh->nlmsg_seq != nlp->seq)
+ /* If the dump got interrupted, we can't rely on the results
+ so try again. */
+ if (nlh->nlmsg_flags & NLM_F_DUMP_INTR)
+ {
+ result = -EAGAIN;
+ goto exit_free;
+ }
if (nlh->nlmsg_type == NLMSG_DONE)
break; /* ok */