kernel/linux.git/net/netfilter/ipvs, branch v5.10.257

ipvs: fix ipv4 null-ptr-deref in route error path

2026-01-19T12:11:42+00:00

[ Upstream commit ad891bb3d079a46a821bf2b8867854645191bab0 ] The IPv4 code path in __ip_vs_get_out_rt() calls dst_link_failure() without ensuring skb->dev is set, leading to a NULL pointer dereference in fib_compute_spec_dst() when ipv4_link_failure() attempts to send ICMP destination unreachable messages. The issue emerged after commit ed0de45a1008 ("ipv4: recompile ip options in ipv4_link_failure") started calling __ip_options_compile() from ipv4_link_failure(). This code path eventually calls fib_compute_spec_dst() which dereferences skb->dev. An attempt was made to fix the NULL skb->dev dereference in commit 0113d9c9d1cc ("ipv4: fix null-deref in ipv4_link_failure"), but it only addressed the immediate dev_net(skb->dev) dereference by using a fallback device. The fix was incomplete because fib_compute_spec_dst() later in the call chain still accesses skb->dev directly, which remains NULL when IPVS calls dst_link_failure(). The crash occurs when: 1. IPVS processes a packet in NAT mode with a misconfigured destination 2. Route lookup fails in __ip_vs_get_out_rt() before establishing a route 3. The error path calls dst_link_failure(skb) with skb->dev == NULL 4. ipv4_link_failure() → ipv4_send_dest_unreach() → __ip_options_compile() → fib_compute_spec_dst() 5. fib_compute_spec_dst() dereferences NULL skb->dev Apply the same fix used for IPv6 in commit 326bf17ea5d4 ("ipvs: fix ipv6 route unreach panic"): set skb->dev from skb_dst(skb)->dev before calling dst_link_failure(). KASAN: null-ptr-deref in range [0x0000000000000328-0x000000000000032f] CPU: 1 PID: 12732 Comm: syz.1.3469 Not tainted 6.6.114 #2 RIP: 0010:__in_dev_get_rcu include/linux/inetdevice.h:233 RIP: 0010:fib_compute_spec_dst+0x17a/0x9f0 net/ipv4/fib_frontend.c:285 Call Trace: spec_dst_fill net/ipv4/ip_options.c:232 spec_dst_fill net/ipv4/ip_options.c:229 __ip_options_compile+0x13a1/0x17d0 net/ipv4/ip_options.c:330 ipv4_send_dest_unreach net/ipv4/route.c:1252 ipv4_link_failure+0x702/0xb80 net/ipv4/route.c:1265 dst_link_failure include/net/dst.h:437 __ip_vs_get_out_rt+0x15fd/0x19e0 net/netfilter/ipvs/ip_vs_xmit.c:412 ip_vs_nat_xmit+0x1d8/0xc80 net/netfilter/ipvs/ip_vs_xmit.c:764 Fixes: ed0de45a1008 ("ipv4: recompile ip options in ipv4_link_failure") Signed-off-by: Slavin Liu Acked-by: Julian Anastasov Signed-off-by: Florian Westphal Signed-off-by: Sasha Levin

ipvs: Defer ip_vs_ftp unregister during netns cleanup

2025-10-29T13:01:07+00:00

[ Upstream commit 134121bfd99a06d44ef5ba15a9beb075297c0821 ] On the netns cleanup path, __ip_vs_ftp_exit() may unregister ip_vs_ftp before connections with valid cp->app pointers are flushed, leading to a use-after-free. Fix this by introducing a global `exiting_module` flag, set to true in ip_vs_ftp_exit() before unregistering the pernet subsystem. In __ip_vs_ftp_exit(), skip ip_vs_ftp unregister if called during netns cleanup (when exiting_module is false) and defer it to __ip_vs_cleanup_batch(), which unregisters all apps after all connections are flushed. If called during module exit, unregister ip_vs_ftp immediately. Fixes: 61b1ab4583e2 ("IPVS: netns, add basic init per netns.") Suggested-by: Julian Anastasov Signed-off-by: Slavin Liu Signed-off-by: Julian Anastasov Signed-off-by: Florian Westphal Signed-off-by: Sasha Levin

ipvs: properly dereference pe in ip_vs_add_service

2025-05-02T05:41:07+00:00

commit cbd070a4ae62f119058973f6d2c984e325bce6e7 upstream. Use pe directly to resolve sparse warning: net/netfilter/ipvs/ip_vs_ctl.c:1471:27: warning: dereference of noderef expression Fixes: 39b972231536 ("ipvs: handle connections started by real-servers") Signed-off-by: Chen Hanxiao Acked-by: Julian Anastasov Acked-by: Simon Horman Signed-off-by: Pablo Neira Ayuso Signed-off-by: Cliff Liu Signed-off-by: He Zhe Signed-off-by: Greg Kroah-Hartman

ipvs: prevent integer overflow in do_ip_vs_get_ctl()

2025-04-10T12:30:49+00:00

[ Upstream commit 80b78c39eb86e6b55f56363b709eb817527da5aa ] The get->num_services variable is an unsigned int which is controlled by the user. The struct_size() function ensures that the size calculation does not overflow an unsigned long, however, we are saving the result to an int so the calculation can overflow. Both "len" and "get->num_services" come from the user. This check is just a sanity check to help the user and ensure they are using the API correctly. An integer overflow here is not a big deal. This has no security impact. Save the result from struct_size() type size_t to fix this integer overflow bug. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Dan Carpenter Acked-by: Julian Anastasov Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin

ipvs: fix UB due to uninitialized stack access in ip_vs_protocol_init()

2024-12-14T18:48:18+00:00

[ Upstream commit 146b6f1112eb30a19776d6c323c994e9d67790db ] Under certain kernel configurations when building with Clang/LLVM, the compiler does not generate a return or jump as the terminator instruction for ip_vs_protocol_init(), triggering the following objtool warning during build time: vmlinux.o: warning: objtool: ip_vs_protocol_init() falls through to next function __initstub__kmod_ip_vs_rr__935_123_ip_vs_rr_init6() At runtime, this either causes an oops when trying to load the ipvs module or a boot-time panic if ipvs is built-in. This same issue has been reported by the Intel kernel test robot previously. Digging deeper into both LLVM and the kernel code reveals this to be a undefined behavior problem. ip_vs_protocol_init() uses a on-stack buffer of 64 chars to store the registered protocol names and leaves it uninitialized after definition. The function calls strnlen() when concatenating protocol names into the buffer. With CONFIG_FORTIFY_SOURCE strnlen() performs an extra step to check whether the last byte of the input char buffer is a null character (commit 3009f891bb9f ("fortify: Allow strlen() and strnlen() to pass compile-time known lengths")). This, together with possibly other configurations, cause the following IR to be generated: define hidden i32 @ip_vs_protocol_init() local_unnamed_addr #5 section ".init.text" align 16 !kcfi_type !29 { %1 = alloca [64 x i8], align 16 ... 14: ; preds = %11 %15 = getelementptr inbounds i8, ptr %1, i64 63 %16 = load i8, ptr %15, align 1 %17 = tail call i1 @llvm.is.constant.i8(i8 %16) %18 = icmp eq i8 %16, 0 %19 = select i1 %17, i1 %18, i1 false br i1 %19, label %20, label %23 20: ; preds = %14 %21 = call i64 @strlen(ptr noundef nonnull dereferenceable(1) %1) #23 ... 23: ; preds = %14, %11, %20 %24 = call i64 @strnlen(ptr noundef nonnull dereferenceable(1) %1, i64 noundef 64) #24 ... } The above code calculates the address of the last char in the buffer (value %15) and then loads from it (value %16). Because the buffer is never initialized, the LLVM GVN pass marks value %16 as undefined: %13 = getelementptr inbounds i8, ptr %1, i64 63 br i1 undef, label %14, label %17 This gives later passes (SCCP, in particular) more DCE opportunities by propagating the undef value further, and eventually removes everything after the load on the uninitialized stack location: define hidden i32 @ip_vs_protocol_init() local_unnamed_addr #0 section ".init.text" align 16 !kcfi_type !11 { %1 = alloca [64 x i8], align 16 ... 12: ; preds = %11 %13 = getelementptr inbounds i8, ptr %1, i64 63 unreachable } In this way, the generated native code will just fall through to the next function, as LLVM does not generate any code for the unreachable IR instruction and leaves the function without a terminator. Zero the on-stack buffer to avoid this possible UB. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202402100205.PWXIz1ZK-lkp@intel.com/ Co-developed-by: Ruowen Qin Signed-off-by: Ruowen Qin Signed-off-by: Jinghao Jia Acked-by: Julian Anastasov Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin

ipvs: Avoid unnecessary calls to skb_is_gso_sctp

2024-08-19T03:40:46+00:00

[ Upstream commit 53796b03295cf7ab1fc8600016fa6dfbf4a494a0 ] In the context of the SCTP SNAT/DNAT handler, these calls can only return true. Fixes: e10d3ba4d434 ("ipvs: Fix checksumming on GSO of SCTP packets") Signed-off-by: Ismael Luceno Acked-by: Julian Anastasov Acked-by: Simon Horman Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin

ipvs: Fix checksumming on GSO of SCTP packets

2024-05-02T14:23:41+00:00

[ Upstream commit e10d3ba4d434ed172914617ed8d74bd411421193 ] It was observed in the wild that pairs of consecutive packets would leave the IPVS with the same wrong checksum, and the issue only went away when disabling GSO. IPVS needs to avoid computing the SCTP checksum when using GSO. Fixes: 90017accff61 ("sctp: Add GSO support") Co-developed-by: Firo Yang Signed-off-by: Ismael Luceno Tested-by: Andreas Taschner Acked-by: Julian Anastasov Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin

ipvs: avoid stat macros calls from preemptible context

2024-01-25T22:37:56+00:00

[ Upstream commit d6938c1c76c64f42363d0d1f051e1b4641c2ad40 ] Inside decrement_ttl() upon discovering that the packet ttl has exceeded, __IP_INC_STATS and __IP6_INC_STATS macros can be called from preemptible context having the following backtrace: check_preemption_disabled: 48 callbacks suppressed BUG: using __this_cpu_add() in preemptible [00000000] code: curl/1177 caller is decrement_ttl+0x217/0x830 CPU: 5 PID: 1177 Comm: curl Not tainted 6.7.0+ #34 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 04/01/2014 Call Trace: dump_stack_lvl+0xbd/0xe0 check_preemption_disabled+0xd1/0xe0 decrement_ttl+0x217/0x830 __ip_vs_get_out_rt+0x4e0/0x1ef0 ip_vs_nat_xmit+0x205/0xcd0 ip_vs_in_hook+0x9b1/0x26a0 nf_hook_slow+0xc2/0x210 nf_hook+0x1fb/0x770 __ip_local_out+0x33b/0x640 ip_local_out+0x2a/0x490 __ip_queue_xmit+0x990/0x1d10 __tcp_transmit_skb+0x288b/0x3d10 tcp_connect+0x3466/0x5180 tcp_v4_connect+0x1535/0x1bb0 __inet_stream_connect+0x40d/0x1040 inet_stream_connect+0x57/0xa0 __sys_connect_file+0x162/0x1a0 __sys_connect+0x137/0x160 __x64_sys_connect+0x72/0xb0 do_syscall_64+0x6f/0x140 entry_SYSCALL_64_after_hwframe+0x6e/0x76 RIP: 0033:0x7fe6dbbc34e0 Use the corresponding preemption-aware variants: IP_INC_STATS and IP6_INC_STATS. Found by Linux Verification Center (linuxtesting.org). Fixes: 8d8e20e2d7bb ("ipvs: Decrement ttl") Signed-off-by: Fedor Pchelkin Acked-by: Julian Anastasov Acked-by: Simon Horman Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin

net: prevent address rewrite in kernel_bind()

2023-10-25T09:54:13+00:00

commit c889a99a21bf124c3db08d09df919f0eccc5ea4c upstream. Similar to the change in commit 0bdf399342c5("net: Avoid address overwrite in kernel_connect"), BPF hooks run on bind may rewrite the address passed to kernel_bind(). This change 1) Makes a copy of the bind address in kernel_bind() to insulate callers. 2) Replaces direct calls to sock->ops->bind() in net with kernel_bind() Link: https://lore.kernel.org/netdev/20230912013332.2048422-1-jrife@google.com/ Fixes: 4fbac77d2d09 ("bpf: Hooks for sys_bind") Cc: stable@vger.kernel.org Reviewed-by: Willem de Bruijn Signed-off-by: Jordan Rife Reviewed-by: Simon Horman Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: replace calls to sock->ops->connect() with kernel_connect()

2023-10-10T19:53:37+00:00

commit 26297b4ce1ce4ea40bc9a48ec99f45da3f64d2e2 upstream. commit 0bdf399342c5 ("net: Avoid address overwrite in kernel_connect") ensured that kernel_connect() will not overwrite the address parameter in cases where BPF connect hooks perform an address rewrite. This change replaces direct calls to sock->ops->connect() in net with kernel_connect() to make these call safe. Link: https://lore.kernel.org/netdev/20230912013332.2048422-1-jrife@google.com/ Fixes: d74bad4e74ee ("bpf: Hooks for sys_connect") Cc: stable@vger.kernel.org Reviewed-by: Willem de Bruijn Signed-off-by: Jordan Rife Reviewed-by: Simon Horman Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman