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| author | Phillip Potter <phil@philpotter.co.uk> | 2021-04-06 18:45:54 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2021-04-06 16:52:21 -0700 |
| commit | cca8ea3b05c972ffb5295367e6c544369b45fbdd (patch) | |
| tree | f13f95fc5dac5b583891c2a2c3c8939602009844 /drivers/net/tun.c | |
| parent | 63cf32389925e234d166fb1a336b46de7f846003 (diff) | |
| download | linux-cca8ea3b05c972ffb5295367e6c544369b45fbdd.tar.gz linux-cca8ea3b05c972ffb5295367e6c544369b45fbdd.tar.bz2 linux-cca8ea3b05c972ffb5295367e6c544369b45fbdd.zip | |
net: tun: set tun->dev->addr_len during TUNSETLINK processing
When changing type with TUNSETLINK ioctl command, set tun->dev->addr_len
to match the appropriate type, using new tun_get_addr_len utility function
which returns appropriate address length for given type. Fixes a
KMSAN-found uninit-value bug reported by syzbot at:
https://syzkaller.appspot.com/bug?id=0766d38c656abeace60621896d705743aeefed51
Reported-by: syzbot+001516d86dbe88862cec@syzkaller.appspotmail.com
Diagnosed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Phillip Potter <phil@philpotter.co.uk>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/tun.c')
| -rw-r--r-- | drivers/net/tun.c | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/drivers/net/tun.c b/drivers/net/tun.c index fc86da7f1628..4cf38be26dc9 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -69,6 +69,14 @@ #include <linux/bpf.h> #include <linux/bpf_trace.h> #include <linux/mutex.h> +#include <linux/ieee802154.h> +#include <linux/if_ltalk.h> +#include <uapi/linux/if_fddi.h> +#include <uapi/linux/if_hippi.h> +#include <uapi/linux/if_fc.h> +#include <net/ax25.h> +#include <net/rose.h> +#include <net/6lowpan.h> #include <linux/uaccess.h> #include <linux/proc_fs.h> @@ -2919,6 +2927,45 @@ static int tun_set_ebpf(struct tun_struct *tun, struct tun_prog __rcu **prog_p, return __tun_set_ebpf(tun, prog_p, prog); } +/* Return correct value for tun->dev->addr_len based on tun->dev->type. */ +static unsigned char tun_get_addr_len(unsigned short type) +{ + switch (type) { + case ARPHRD_IP6GRE: + case ARPHRD_TUNNEL6: + return sizeof(struct in6_addr); + case ARPHRD_IPGRE: + case ARPHRD_TUNNEL: + case ARPHRD_SIT: + return 4; + case ARPHRD_ETHER: + return ETH_ALEN; + case ARPHRD_IEEE802154: + case ARPHRD_IEEE802154_MONITOR: + return IEEE802154_EXTENDED_ADDR_LEN; + case ARPHRD_PHONET_PIPE: + case ARPHRD_PPP: + case ARPHRD_NONE: + return 0; + case ARPHRD_6LOWPAN: + return EUI64_ADDR_LEN; + case ARPHRD_FDDI: + return FDDI_K_ALEN; + case ARPHRD_HIPPI: + return HIPPI_ALEN; + case ARPHRD_IEEE802: + return FC_ALEN; + case ARPHRD_ROSE: + return ROSE_ADDR_LEN; + case ARPHRD_NETROM: + return AX25_ADDR_LEN; + case ARPHRD_LOCALTLK: + return LTALK_ALEN; + default: + return 0; + } +} + static long __tun_chr_ioctl(struct file *file, unsigned int cmd, unsigned long arg, int ifreq_len) { @@ -3082,6 +3129,7 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd, break; } tun->dev->type = (int) arg; + tun->dev->addr_len = tun_get_addr_len(tun->dev->type); netif_info(tun, drv, tun->dev, "linktype set to %d\n", tun->dev->type); call_netdevice_notifiers(NETDEV_POST_TYPE_CHANGE, |