| Message ID | 20230926125120.152133-1-syoshida@redhat.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | tipc: Fix uninit-value access in __tipc_nl_bearer_enable() | expand |
On Tue, Sep 26, 2023 at 09:51:20PM +0900, Shigeru Yoshida wrote: > syzbot reported the following uninit-value access issue: > > ===================================================== > BUG: KMSAN: uninit-value in strscpy+0xc4/0x160 > strscpy+0xc4/0x160 > bearer_name_validate net/tipc/bearer.c:147 [inline] > tipc_enable_bearer net/tipc/bearer.c:259 [inline] > __tipc_nl_bearer_enable+0x634/0x2220 net/tipc/bearer.c:1043 > tipc_nl_bearer_enable+0x3c/0x70 net/tipc/bearer.c:1052 > genl_family_rcv_msg_doit net/netlink/genetlink.c:971 [inline] > genl_family_rcv_msg net/netlink/genetlink.c:1051 [inline] > genl_rcv_msg+0x11ec/0x1290 net/netlink/genetlink.c:1066 > netlink_rcv_skb+0x371/0x650 net/netlink/af_netlink.c:2545 > genl_rcv+0x40/0x60 net/netlink/genetlink.c:1075 > netlink_unicast_kernel net/netlink/af_netlink.c:1342 [inline] > netlink_unicast+0xf47/0x1250 net/netlink/af_netlink.c:1368 > netlink_sendmsg+0x1238/0x13d0 net/netlink/af_netlink.c:1910 > sock_sendmsg_nosec net/socket.c:730 [inline] > sock_sendmsg net/socket.c:753 [inline] > ____sys_sendmsg+0x9c2/0xd60 net/socket.c:2540 > ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2594 > __sys_sendmsg net/socket.c:2623 [inline] > __do_sys_sendmsg net/socket.c:2632 [inline] > __se_sys_sendmsg net/socket.c:2630 [inline] > __x64_sys_sendmsg+0x307/0x490 net/socket.c:2630 > do_syscall_x64 arch/x86/entry/common.c:50 [inline] > do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 > entry_SYSCALL_64_after_hwframe+0x63/0xcd > > Uninit was created at: > slab_post_alloc_hook+0x12f/0xb70 mm/slab.h:767 > slab_alloc_node mm/slub.c:3478 [inline] > kmem_cache_alloc_node+0x577/0xa80 mm/slub.c:3523 > kmalloc_reserve+0x148/0x470 net/core/skbuff.c:559 > __alloc_skb+0x318/0x740 net/core/skbuff.c:644 > alloc_skb include/linux/skbuff.h:1286 [inline] > netlink_alloc_large_skb net/netlink/af_netlink.c:1214 [inline] > netlink_sendmsg+0xb34/0x13d0 net/netlink/af_netlink.c:1885 > sock_sendmsg_nosec net/socket.c:730 [inline] > sock_sendmsg net/socket.c:753 [inline] > ____sys_sendmsg+0x9c2/0xd60 net/socket.c:2540 > ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2594 > __sys_sendmsg net/socket.c:2623 [inline] > __do_sys_sendmsg net/socket.c:2632 [inline] > __se_sys_sendmsg net/socket.c:2630 [inline] > __x64_sys_sendmsg+0x307/0x490 net/socket.c:2630 > do_syscall_x64 arch/x86/entry/common.c:50 [inline] > do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 > entry_SYSCALL_64_after_hwframe+0x63/0xcd > > Bearer names must be null-terminated strings. If a bearer name which is not > null-terminated is passed through netlink, strcpy() and similar functions > can cause buffer overrun. This causes the above issue. > > This patch fixes this issue by returning -EINVAL if a non-null-terminated > bearer name is passed. > > Fixes: 0655f6a8635b ("tipc: add bearer disable/enable to new netlink api") > Reported-and-tested-by: syzbot+9425c47dccbcb4c17d51@syzkaller.appspotmail.com > Closes: https://syzkaller.appspot.com/bug?extid=9425c47dccbcb4c17d51 > Signed-off-by: Shigeru Yoshida <syoshida@redhat.com> Reviewed-by: Simon Horman <horms@kernel.org>
On Tue, 2023-09-26 at 21:51 +0900, Shigeru Yoshida wrote: > syzbot reported the following uninit-value access issue: > > ===================================================== > BUG: KMSAN: uninit-value in strscpy+0xc4/0x160 > strscpy+0xc4/0x160 > bearer_name_validate net/tipc/bearer.c:147 [inline] > tipc_enable_bearer net/tipc/bearer.c:259 [inline] > __tipc_nl_bearer_enable+0x634/0x2220 net/tipc/bearer.c:1043 > tipc_nl_bearer_enable+0x3c/0x70 net/tipc/bearer.c:1052 > genl_family_rcv_msg_doit net/netlink/genetlink.c:971 [inline] > genl_family_rcv_msg net/netlink/genetlink.c:1051 [inline] > genl_rcv_msg+0x11ec/0x1290 net/netlink/genetlink.c:1066 > netlink_rcv_skb+0x371/0x650 net/netlink/af_netlink.c:2545 > genl_rcv+0x40/0x60 net/netlink/genetlink.c:1075 > netlink_unicast_kernel net/netlink/af_netlink.c:1342 [inline] > netlink_unicast+0xf47/0x1250 net/netlink/af_netlink.c:1368 > netlink_sendmsg+0x1238/0x13d0 net/netlink/af_netlink.c:1910 > sock_sendmsg_nosec net/socket.c:730 [inline] > sock_sendmsg net/socket.c:753 [inline] > ____sys_sendmsg+0x9c2/0xd60 net/socket.c:2540 > ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2594 > __sys_sendmsg net/socket.c:2623 [inline] > __do_sys_sendmsg net/socket.c:2632 [inline] > __se_sys_sendmsg net/socket.c:2630 [inline] > __x64_sys_sendmsg+0x307/0x490 net/socket.c:2630 > do_syscall_x64 arch/x86/entry/common.c:50 [inline] > do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 > entry_SYSCALL_64_after_hwframe+0x63/0xcd > > Uninit was created at: > slab_post_alloc_hook+0x12f/0xb70 mm/slab.h:767 > slab_alloc_node mm/slub.c:3478 [inline] > kmem_cache_alloc_node+0x577/0xa80 mm/slub.c:3523 > kmalloc_reserve+0x148/0x470 net/core/skbuff.c:559 > __alloc_skb+0x318/0x740 net/core/skbuff.c:644 > alloc_skb include/linux/skbuff.h:1286 [inline] > netlink_alloc_large_skb net/netlink/af_netlink.c:1214 [inline] > netlink_sendmsg+0xb34/0x13d0 net/netlink/af_netlink.c:1885 > sock_sendmsg_nosec net/socket.c:730 [inline] > sock_sendmsg net/socket.c:753 [inline] > ____sys_sendmsg+0x9c2/0xd60 net/socket.c:2540 > ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2594 > __sys_sendmsg net/socket.c:2623 [inline] > __do_sys_sendmsg net/socket.c:2632 [inline] > __se_sys_sendmsg net/socket.c:2630 [inline] > __x64_sys_sendmsg+0x307/0x490 net/socket.c:2630 > do_syscall_x64 arch/x86/entry/common.c:50 [inline] > do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 > entry_SYSCALL_64_after_hwframe+0x63/0xcd > > Bearer names must be null-terminated strings. If a bearer name which is not > null-terminated is passed through netlink, strcpy() and similar functions > can cause buffer overrun. This causes the above issue. > > This patch fixes this issue by returning -EINVAL if a non-null-terminated > bearer name is passed. > > Fixes: 0655f6a8635b ("tipc: add bearer disable/enable to new netlink api") > Reported-and-tested-by: syzbot+9425c47dccbcb4c17d51@syzkaller.appspotmail.com > Closes: https://syzkaller.appspot.com/bug?extid=9425c47dccbcb4c17d51 > Signed-off-by: Shigeru Yoshida <syoshida@redhat.com> > --- > net/tipc/bearer.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/net/tipc/bearer.c b/net/tipc/bearer.c > index 2cde375477e3..62047d20e14d 100644 > --- a/net/tipc/bearer.c > +++ b/net/tipc/bearer.c > @@ -1025,6 +1025,10 @@ int __tipc_nl_bearer_enable(struct sk_buff *skb, struct genl_info *info) > > bearer = nla_data(attrs[TIPC_NLA_BEARER_NAME]); > > + if (bearer[strnlen(bearer, > + nla_len(attrs[TIPC_NLA_BEARER_NAME]))] != '\0') if 'bearer' is not NULL terminated, the above will access the first byte after the TIPC_NLA_BEARER_NAME attribute. I think it would cleaner and safer using nla_strscpy() instead. Quickly skimming over the tpic code, most TIPC_NLA_BEARER_NAME access looks unsafe, and possibly a similar fix should be applied in more places. Thanks, Paolo
On Tue, 03 Oct 2023 10:52:50 +0200, Paolo Abeni wrote: > On Tue, 2023-09-26 at 21:51 +0900, Shigeru Yoshida wrote: >> syzbot reported the following uninit-value access issue: >> >> ===================================================== >> BUG: KMSAN: uninit-value in strscpy+0xc4/0x160 >> strscpy+0xc4/0x160 >> bearer_name_validate net/tipc/bearer.c:147 [inline] >> tipc_enable_bearer net/tipc/bearer.c:259 [inline] >> __tipc_nl_bearer_enable+0x634/0x2220 net/tipc/bearer.c:1043 >> tipc_nl_bearer_enable+0x3c/0x70 net/tipc/bearer.c:1052 >> genl_family_rcv_msg_doit net/netlink/genetlink.c:971 [inline] >> genl_family_rcv_msg net/netlink/genetlink.c:1051 [inline] >> genl_rcv_msg+0x11ec/0x1290 net/netlink/genetlink.c:1066 >> netlink_rcv_skb+0x371/0x650 net/netlink/af_netlink.c:2545 >> genl_rcv+0x40/0x60 net/netlink/genetlink.c:1075 >> netlink_unicast_kernel net/netlink/af_netlink.c:1342 [inline] >> netlink_unicast+0xf47/0x1250 net/netlink/af_netlink.c:1368 >> netlink_sendmsg+0x1238/0x13d0 net/netlink/af_netlink.c:1910 >> sock_sendmsg_nosec net/socket.c:730 [inline] >> sock_sendmsg net/socket.c:753 [inline] >> ____sys_sendmsg+0x9c2/0xd60 net/socket.c:2540 >> ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2594 >> __sys_sendmsg net/socket.c:2623 [inline] >> __do_sys_sendmsg net/socket.c:2632 [inline] >> __se_sys_sendmsg net/socket.c:2630 [inline] >> __x64_sys_sendmsg+0x307/0x490 net/socket.c:2630 >> do_syscall_x64 arch/x86/entry/common.c:50 [inline] >> do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 >> entry_SYSCALL_64_after_hwframe+0x63/0xcd >> >> Uninit was created at: >> slab_post_alloc_hook+0x12f/0xb70 mm/slab.h:767 >> slab_alloc_node mm/slub.c:3478 [inline] >> kmem_cache_alloc_node+0x577/0xa80 mm/slub.c:3523 >> kmalloc_reserve+0x148/0x470 net/core/skbuff.c:559 >> __alloc_skb+0x318/0x740 net/core/skbuff.c:644 >> alloc_skb include/linux/skbuff.h:1286 [inline] >> netlink_alloc_large_skb net/netlink/af_netlink.c:1214 [inline] >> netlink_sendmsg+0xb34/0x13d0 net/netlink/af_netlink.c:1885 >> sock_sendmsg_nosec net/socket.c:730 [inline] >> sock_sendmsg net/socket.c:753 [inline] >> ____sys_sendmsg+0x9c2/0xd60 net/socket.c:2540 >> ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2594 >> __sys_sendmsg net/socket.c:2623 [inline] >> __do_sys_sendmsg net/socket.c:2632 [inline] >> __se_sys_sendmsg net/socket.c:2630 [inline] >> __x64_sys_sendmsg+0x307/0x490 net/socket.c:2630 >> do_syscall_x64 arch/x86/entry/common.c:50 [inline] >> do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 >> entry_SYSCALL_64_after_hwframe+0x63/0xcd >> >> Bearer names must be null-terminated strings. If a bearer name which is not >> null-terminated is passed through netlink, strcpy() and similar functions >> can cause buffer overrun. This causes the above issue. >> >> This patch fixes this issue by returning -EINVAL if a non-null-terminated >> bearer name is passed. >> >> Fixes: 0655f6a8635b ("tipc: add bearer disable/enable to new netlink api") >> Reported-and-tested-by: syzbot+9425c47dccbcb4c17d51@syzkaller.appspotmail.com >> Closes: https://syzkaller.appspot.com/bug?extid=9425c47dccbcb4c17d51 >> Signed-off-by: Shigeru Yoshida <syoshida@redhat.com> >> --- >> net/tipc/bearer.c | 4 ++++ >> 1 file changed, 4 insertions(+) >> >> diff --git a/net/tipc/bearer.c b/net/tipc/bearer.c >> index 2cde375477e3..62047d20e14d 100644 >> --- a/net/tipc/bearer.c >> +++ b/net/tipc/bearer.c >> @@ -1025,6 +1025,10 @@ int __tipc_nl_bearer_enable(struct sk_buff *skb, struct genl_info *info) >> >> bearer = nla_data(attrs[TIPC_NLA_BEARER_NAME]); >> >> + if (bearer[strnlen(bearer, >> + nla_len(attrs[TIPC_NLA_BEARER_NAME]))] != '\0') > > if 'bearer' is not NULL terminated, the above will access the first > byte after the TIPC_NLA_BEARER_NAME attribute. > > I think it would cleaner and safer using nla_strscpy() instead. Thank you so much for your comment. I didn't notice the existence of nla_strscpy(). > Quickly skimming over the tpic code, most TIPC_NLA_BEARER_NAME access > looks unsafe, and possibly a similar fix should be applied in more > places. I've checked the usage of TIPC_NLA_BEARER_NAME accesses. These might cause the same issue, so the same fix should be needed, as you say. I'll send a v2 patch. Thanks, Shigeru > > Thanks, > > Paolo >
diff --git a/net/tipc/bearer.c b/net/tipc/bearer.c index 2cde375477e3..62047d20e14d 100644 --- a/net/tipc/bearer.c +++ b/net/tipc/bearer.c @@ -1025,6 +1025,10 @@ int __tipc_nl_bearer_enable(struct sk_buff *skb, struct genl_info *info) bearer = nla_data(attrs[TIPC_NLA_BEARER_NAME]); + if (bearer[strnlen(bearer, + nla_len(attrs[TIPC_NLA_BEARER_NAME]))] != '\0') + return -EINVAL; + if (attrs[TIPC_NLA_BEARER_DOMAIN]) domain = nla_get_u32(attrs[TIPC_NLA_BEARER_DOMAIN]);
syzbot reported the following uninit-value access issue: ===================================================== BUG: KMSAN: uninit-value in strscpy+0xc4/0x160 strscpy+0xc4/0x160 bearer_name_validate net/tipc/bearer.c:147 [inline] tipc_enable_bearer net/tipc/bearer.c:259 [inline] __tipc_nl_bearer_enable+0x634/0x2220 net/tipc/bearer.c:1043 tipc_nl_bearer_enable+0x3c/0x70 net/tipc/bearer.c:1052 genl_family_rcv_msg_doit net/netlink/genetlink.c:971 [inline] genl_family_rcv_msg net/netlink/genetlink.c:1051 [inline] genl_rcv_msg+0x11ec/0x1290 net/netlink/genetlink.c:1066 netlink_rcv_skb+0x371/0x650 net/netlink/af_netlink.c:2545 genl_rcv+0x40/0x60 net/netlink/genetlink.c:1075 netlink_unicast_kernel net/netlink/af_netlink.c:1342 [inline] netlink_unicast+0xf47/0x1250 net/netlink/af_netlink.c:1368 netlink_sendmsg+0x1238/0x13d0 net/netlink/af_netlink.c:1910 sock_sendmsg_nosec net/socket.c:730 [inline] sock_sendmsg net/socket.c:753 [inline] ____sys_sendmsg+0x9c2/0xd60 net/socket.c:2540 ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2594 __sys_sendmsg net/socket.c:2623 [inline] __do_sys_sendmsg net/socket.c:2632 [inline] __se_sys_sendmsg net/socket.c:2630 [inline] __x64_sys_sendmsg+0x307/0x490 net/socket.c:2630 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Uninit was created at: slab_post_alloc_hook+0x12f/0xb70 mm/slab.h:767 slab_alloc_node mm/slub.c:3478 [inline] kmem_cache_alloc_node+0x577/0xa80 mm/slub.c:3523 kmalloc_reserve+0x148/0x470 net/core/skbuff.c:559 __alloc_skb+0x318/0x740 net/core/skbuff.c:644 alloc_skb include/linux/skbuff.h:1286 [inline] netlink_alloc_large_skb net/netlink/af_netlink.c:1214 [inline] netlink_sendmsg+0xb34/0x13d0 net/netlink/af_netlink.c:1885 sock_sendmsg_nosec net/socket.c:730 [inline] sock_sendmsg net/socket.c:753 [inline] ____sys_sendmsg+0x9c2/0xd60 net/socket.c:2540 ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2594 __sys_sendmsg net/socket.c:2623 [inline] __do_sys_sendmsg net/socket.c:2632 [inline] __se_sys_sendmsg net/socket.c:2630 [inline] __x64_sys_sendmsg+0x307/0x490 net/socket.c:2630 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Bearer names must be null-terminated strings. If a bearer name which is not null-terminated is passed through netlink, strcpy() and similar functions can cause buffer overrun. This causes the above issue. This patch fixes this issue by returning -EINVAL if a non-null-terminated bearer name is passed. Fixes: 0655f6a8635b ("tipc: add bearer disable/enable to new netlink api") Reported-and-tested-by: syzbot+9425c47dccbcb4c17d51@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=9425c47dccbcb4c17d51 Signed-off-by: Shigeru Yoshida <syoshida@redhat.com> --- net/tipc/bearer.c | 4 ++++ 1 file changed, 4 insertions(+)