[syzbot ci] Re: pull-request: can-next 2025-09-24

[syzbot ci <syzbot+ci284feacb80736eb0@syzkaller.appspotmail.com>]

syzbot ci has tested the following series

[v1] pull-request: can-next 2025-09-24
https://lore.kernel.org/all/20250924082104.595459-1-mkl@pengutronix.de
* [PATCH net-next 01/48] can: m_can: use us_to_ktime() where appropriate
* [PATCH net-next 02/48] MAINTAINERS: update Vincent Mailhol's email address
* [PATCH net-next 03/48] can: dev: sort includes by alphabetical order
* [PATCH net-next 04/48] can: peak: Modification of references to email accounts being deleted
* [PATCH net-next 05/48] can: rcar_canfd: Update bit rate constants for RZ/G3E and R-Car Gen4
* [PATCH net-next 06/48] can: rcar_canfd: Update RCANFD_CFG_* macros
* [PATCH net-next 07/48] can: rcar_canfd: Simplify nominal bit rate config
* [PATCH net-next 08/48] can: rcar_canfd: Simplify data bit rate config
* [PATCH net-next 09/48] can: rcar_can: Consistently use ndev for net_device pointers
* [PATCH net-next 10/48] can: rcar_can: Add helper variable dev to rcar_can_probe()
* [PATCH net-next 11/48] can: rcar_can: Convert to Runtime PM
* [PATCH net-next 12/48] can: rcar_can: Convert to BIT()
* [PATCH net-next 13/48] can: rcar_can: Convert to GENMASK()
* [PATCH net-next 14/48] can: rcar_can: CTLR bitfield conversion
* [PATCH net-next 15/48] can: rcar_can: TFCR bitfield conversion
* [PATCH net-next 16/48] can: rcar_can: BCR bitfield conversion
* [PATCH net-next 17/48] can: rcar_can: Mailbox bitfield conversion
* [PATCH net-next 18/48] can: rcar_can: Do not print alloc_candev() failures
* [PATCH net-next 19/48] can: rcar_can: Convert to %pe
* [PATCH net-next 20/48] can: esd_usb: Rework display of error messages
* [PATCH net-next 21/48] can: esd_usb: Avoid errors triggered from USB disconnect
* [PATCH net-next 22/48] can: raw: reorder struct uniqframe's members to optimise packing
* [PATCH net-next 23/48] can: raw: use bitfields to store flags in struct raw_sock
* [PATCH net-next 24/48] can: raw: reorder struct raw_sock's members to optimise packing
* [PATCH net-next 25/48] can: annotate mtu accesses with READ_ONCE()
* [PATCH net-next 26/48] can: dev: turn can_set_static_ctrlmode() into a non-inline function
* [PATCH net-next 27/48] can: populate the minimum and maximum MTU values
* [PATCH net-next 28/48] can: enable CAN XL for virtual CAN devices by default
* [PATCH net-next 29/48] can: dev: move struct data_bittiming_params to linux/can/bittiming.h
* [PATCH net-next 30/48] can: dev: make can_get_relative_tdco() FD agnostic and move it to bittiming.h
* [PATCH net-next 31/48] can: netlink: document which symbols are FD specific
* [PATCH net-next 32/48] can: netlink: refactor can_validate_bittiming()
* [PATCH net-next 33/48] can: netlink: add can_validate_tdc()
* [PATCH net-next 34/48] can: netlink: add can_validate_databittiming()
* [PATCH net-next 35/48] can: netlink: refactor CAN_CTRLMODE_TDC_{AUTO,MANUAL} flag reset logic
* [PATCH net-next 36/48] can: netlink: remove useless check in can_tdc_changelink()
* [PATCH net-next 37/48] can: netlink: make can_tdc_changelink() FD agnostic
* [PATCH net-next 38/48] can: netlink: add can_dtb_changelink()
* [PATCH net-next 39/48] can: netlink: add can_ctrlmode_changelink()
* [PATCH net-next 40/48] can: netlink: make can_tdc_get_size() FD agnostic
* [PATCH net-next 41/48] can: netlink: add can_data_bittiming_get_size()
* [PATCH net-next 42/48] can: netlink: add can_bittiming_fill_info()
* [PATCH net-next 43/48] can: netlink: add can_bittiming_const_fill_info()
* [PATCH net-next 44/48] can: netlink: add can_bitrate_const_fill_info()
* [PATCH net-next 45/48] can: netlink: make can_tdc_fill_info() FD agnostic
* [PATCH net-next 46/48] can: calc_bittiming: make can_calc_tdco() FD agnostic
* [PATCH net-next 47/48] can: dev: add can_get_ctrlmode_str()
* [PATCH net-next 48/48] can: netlink: add userland error messages

and found the following issue:
KASAN: slab-out-of-bounds Read in can_setup

Full report is available here:
https://ci.syzbot.org/series/7feff13b-7247-438c-9d92-b8e9fda977c7

***

KASAN: slab-out-of-bounds Read in can_setup

tree:      net-next
URL:       https://kernel.googlesource.com/pub/scm/linux/kernel/git/netdev/net-next.git
base:      315f423be0d1ebe720d8fd4fa6bed68586b13d34
arch:      amd64
compiler:  Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
config:    https://ci.syzbot.org/builds/08331a39-4a31-4f96-a377-3125df2af883/config
C repro:   https://ci.syzbot.org/findings/46cae752-cb54-4ceb-87cb-bb9d2fdb1d79/c_repro
syz repro: https://ci.syzbot.org/findings/46cae752-cb54-4ceb-87cb-bb9d2fdb1d79/syz_repro

netlink: 24 bytes leftover after parsing attributes in process `syz.0.17'.
==================================================================
BUG: KASAN: slab-out-of-bounds in can_set_default_mtu drivers/net/can/dev/dev.c:350 [inline]
BUG: KASAN: slab-out-of-bounds in can_setup+0x209/0x280 drivers/net/can/dev/dev.c:279
Read of size 4 at addr ffff888106a6ee74 by task syz.0.17/5999

CPU: 1 UID: 0 PID: 5999 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xca/0x240 mm/kasan/report.c:482
 kasan_report+0x118/0x150 mm/kasan/report.c:595
 can_set_default_mtu drivers/net/can/dev/dev.c:350 [inline]
 can_setup+0x209/0x280 drivers/net/can/dev/dev.c:279
 alloc_netdev_mqs+0x795/0x11b0 net/core/dev.c:11949
 rtnl_create_link+0x31f/0xd10 net/core/rtnetlink.c:3633
 rtnl_newlink_create+0x25c/0xb00 net/core/rtnetlink.c:3815
 __rtnl_newlink net/core/rtnetlink.c:3942 [inline]
 rtnl_newlink+0x16d6/0x1c70 net/core/rtnetlink.c:4057
 rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6946
 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2552
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896
 sock_sendmsg_nosec net/socket.c:714 [inline]
 __sock_sendmsg+0x21c/0x270 net/socket.c:729
 ____sys_sendmsg+0x505/0x830 net/socket.c:2614
 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2668
 __sys_sendmsg net/socket.c:2700 [inline]
 __do_sys_sendmsg net/socket.c:2705 [inline]
 __se_sys_sendmsg net/socket.c:2703 [inline]
 __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2703
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0b7658ec29
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff71a7bdf8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f0b767d5fa0 RCX: 00007f0b7658ec29
RDX: 0000000000000000 RSI: 0000200000000280 RDI: 0000000000000003
RBP: 00007f0b76611e41 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0b767d5fa0 R14: 00007f0b767d5fa0 R15: 0000000000000003
 </TASK>

Allocated by task 5999:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:388 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:405
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __do_kmalloc_node mm/slub.c:4376 [inline]
 __kvmalloc_node_noprof+0x30d/0x5f0 mm/slub.c:5067
 alloc_netdev_mqs+0xa3/0x11b0 net/core/dev.c:11893
 rtnl_create_link+0x31f/0xd10 net/core/rtnetlink.c:3633
 rtnl_newlink_create+0x25c/0xb00 net/core/rtnetlink.c:3815
 __rtnl_newlink net/core/rtnetlink.c:3942 [inline]
 rtnl_newlink+0x16d6/0x1c70 net/core/rtnetlink.c:4057
 rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6946
 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2552
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896
 sock_sendmsg_nosec net/socket.c:714 [inline]
 __sock_sendmsg+0x21c/0x270 net/socket.c:729
 ____sys_sendmsg+0x505/0x830 net/socket.c:2614
 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2668
 __sys_sendmsg net/socket.c:2700 [inline]
 __do_sys_sendmsg net/socket.c:2705 [inline]
 __se_sys_sendmsg net/socket.c:2703 [inline]
 __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2703
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888106a6e000
 which belongs to the cache kmalloc-cg-4k of size 4096
The buggy address is located 244 bytes to the right of
 allocated 3456-byte region [ffff888106a6e000, ffff888106a6ed80)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x106a68
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff88810e6ebb41
flags: 0x57ff00000000040(head|node=1|zone=2|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 057ff00000000040 ffff88801a44b500 ffffea00043e4000 dead000000000002
raw: 0000000000000000 0000000080040004 00000000f5000000 ffff88810e6ebb41
head: 057ff00000000040 ffff88801a44b500 ffffea00043e4000 dead000000000002
head: 0000000000000000 0000000080040004 00000000f5000000 ffff88810e6ebb41
head: 057ff00000000003 ffffea00041a9a01 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd60c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_RETRY_MAYFAIL|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5901, tgid 5901 (syz-executor), ts 69629116017, free_ts 69616324772
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1851
 prep_new_page mm/page_alloc.c:1859 [inline]
 get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3858
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5148
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416
 alloc_slab_page mm/slub.c:2492 [inline]
 allocate_slab+0x8a/0x370 mm/slub.c:2660
 new_slab mm/slub.c:2714 [inline]
 ___slab_alloc+0xbeb/0x1420 mm/slub.c:3901
 __slab_alloc mm/slub.c:3992 [inline]
 __slab_alloc_node mm/slub.c:4067 [inline]
 slab_alloc_node mm/slub.c:4228 [inline]
 __do_kmalloc_node mm/slub.c:4375 [inline]
 __kvmalloc_node_noprof+0x429/0x5f0 mm/slub.c:5067
 alloc_netdev_mqs+0xa3/0x11b0 net/core/dev.c:11893
 vti6_init_net+0x104/0x370 net/ipv6/ip6_vti.c:1146
 ops_init+0x35c/0x5c0 net/core/net_namespace.c:136
 setup_net+0x10c/0x320 net/core/net_namespace.c:438
 copy_net_ns+0x31b/0x4d0 net/core/net_namespace.c:570
 create_new_namespaces+0x3f3/0x720 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0x11c/0x170 kernel/nsproxy.c:218
 ksys_unshare+0x4c8/0x8c0 kernel/fork.c:3127
 __do_sys_unshare kernel/fork.c:3198 [inline]
 __se_sys_unshare kernel/fork.c:3196 [inline]
 __x64_sys_unshare+0x38/0x50 kernel/fork.c:3196
page last free pid 5901 tgid 5901 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1395 [inline]
 __free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2895
 __slab_free+0x303/0x3c0 mm/slub.c:4606
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:340
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4191 [inline]
 slab_alloc_node mm/slub.c:4240 [inline]
 __kmalloc_cache_noprof+0x1be/0x3d0 mm/slub.c:4402
 kmalloc_noprof include/linux/slab.h:905 [inline]
 kzalloc_noprof include/linux/slab.h:1039 [inline]
 ref_tracker_alloc+0x133/0x460 lib/ref_tracker.c:271
 __netdev_tracker_alloc include/linux/netdevice.h:4379 [inline]
 netdev_hold include/linux/netdevice.h:4408 [inline]
 netdev_queue_add_kobject net/core/net-sysfs.c:1994 [inline]
 netdev_queue_update_kobjects+0x1d1/0x6c0 net/core/net-sysfs.c:2056
 register_queue_kobjects net/core/net-sysfs.c:2119 [inline]
 netdev_register_kobject+0x258/0x310 net/core/net-sysfs.c:2362
 register_netdevice+0x126c/0x1ae0 net/core/dev.c:11287
 __ip_tunnel_create+0x3e7/0x560 net/ipv4/ip_tunnel.c:268
 ip_tunnel_init_net+0x2ba/0x800 net/ipv4/ip_tunnel.c:1161
 ops_init+0x35c/0x5c0 net/core/net_namespace.c:136
 setup_net+0x10c/0x320 net/core/net_namespace.c:438
 copy_net_ns+0x31b/0x4d0 net/core/net_namespace.c:570
 create_new_namespaces+0x3f3/0x720 kernel/nsproxy.c:110

Memory state around the buggy address:
 ffff888106a6ed00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888106a6ed80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888106a6ee00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                                             ^
 ffff888106a6ee80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888106a6ef00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================


***

If these findings have caused you to resend the series or submit a
separate fix, please add the following tag to your commit message:
  Tested-by: syzbot@syzkaller.appspotmail.com

---
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syzbot ci engineers can be reached at syzkaller@googlegroups.com.