6.1-stable review patch. If anyone has any objections, please let me know.
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From: Christoph Paasch cpaasch@apple.com
commit 503930f8e113edc86f92b767efb4ea57bdffffb2 upstream.
rtnl_offload_xstats_get_size_hw_s_info_one() conditionalizes the size-computation for IFLA_OFFLOAD_XSTATS_HW_S_INFO_USED based on whether or not the device has offload_xstats enabled.
However, rtnl_offload_xstats_fill_hw_s_info_one() is adding the u8 for that field uncondtionally.
syzkaller triggered a WARNING in rtnl_stats_get due to this: ------------[ cut here ]------------ WARNING: CPU: 0 PID: 754 at net/core/rtnetlink.c:5982 rtnl_stats_get+0x2f4/0x300 Modules linked in: CPU: 0 PID: 754 Comm: syz-executor148 Not tainted 6.6.0-rc2-g331b78eb12af #45 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014 RIP: 0010:rtnl_stats_get+0x2f4/0x300 net/core/rtnetlink.c:5982 Code: ff ff 89 ee e8 7d 72 50 ff 83 fd a6 74 17 e8 33 6e 50 ff 4c 89 ef be 02 00 00 00 e8 86 00 fa ff e9 7b fe ff ff e8 1c 6e 50 ff <0f> 0b eb e5 e8 73 79 7b 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc900006837c0 EFLAGS: 00010293 RAX: ffffffff81cf7f24 RBX: ffff8881015d9000 RCX: ffff888101815a00 RDX: 0000000000000000 RSI: 00000000ffffffa6 RDI: 00000000ffffffa6 RBP: 00000000ffffffa6 R08: ffffffff81cf7f03 R09: 0000000000000001 R10: ffff888101ba47b9 R11: ffff888101815a00 R12: ffff8881017dae00 R13: ffff8881017dad00 R14: ffffc90000683ab8 R15: ffffffff83c1f740 FS: 00007fbc22dbc740(0000) GS:ffff88813bc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000046 CR3: 000000010264e003 CR4: 0000000000170ef0 Call Trace: <TASK> rtnetlink_rcv_msg+0x677/0x710 net/core/rtnetlink.c:6480 netlink_rcv_skb+0xea/0x1c0 net/netlink/af_netlink.c:2545 netlink_unicast+0x430/0x500 net/netlink/af_netlink.c:1342 netlink_sendmsg+0x4fc/0x620 net/netlink/af_netlink.c:1910 sock_sendmsg+0xa8/0xd0 net/socket.c:730 ____sys_sendmsg+0x22a/0x320 net/socket.c:2541 ___sys_sendmsg+0x143/0x190 net/socket.c:2595 __x64_sys_sendmsg+0xd8/0x150 net/socket.c:2624 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x47/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x6e/0xd8 RIP: 0033:0x7fbc22e8d6a9 Code: 5c c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 4f 37 0d 00 f7 d8 64 89 01 48 RSP: 002b:00007ffc4320e778 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00000000004007d0 RCX: 00007fbc22e8d6a9 RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000003 RBP: 0000000000000001 R08: 0000000000000000 R09: 00000000004007d0 R10: 0000000000000008 R11: 0000000000000246 R12: 00007ffc4320e898 R13: 00007ffc4320e8a8 R14: 00000000004004a0 R15: 00007fbc22fa5a80 </TASK> ---[ end trace 0000000000000000 ]---
Which didn't happen prior to commit bf9f1baa279f ("net: add dedicated kmem_cache for typical/small skb->head") as the skb always was large enough.
Fixes: 0e7788fd7622 ("net: rtnetlink: Add UAPI for obtaining L3 offload xstats") Signed-off-by: Christoph Paasch cpaasch@apple.com Reviewed-by: Petr Machata petrm@nvidia.com Link: https://lore.kernel.org/r/20231013041448.8229-1-cpaasch@apple.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/core/rtnetlink.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-)
--- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -5394,13 +5394,11 @@ static unsigned int rtnl_offload_xstats_get_size_hw_s_info_one(const struct net_device *dev, enum netdev_offload_xstats_type type) { - bool enabled = netdev_offload_xstats_enabled(dev, type); - return nla_total_size(0) + /* IFLA_OFFLOAD_XSTATS_HW_S_INFO_REQUEST */ nla_total_size(sizeof(u8)) + /* IFLA_OFFLOAD_XSTATS_HW_S_INFO_USED */ - (enabled ? nla_total_size(sizeof(u8)) : 0) + + nla_total_size(sizeof(u8)) + 0; }