ci2 starts bisection 2026-09-27 11:55:14.845867517 +0000 UTC m=+120316.169179996 bisecting fixing commit since 447db0046f21df411c817f9f05b9f6210adb9d81 building syzkaller on 5d63f80b763910b40ae04a96c13dc75d621bea67 ensuring issue is reproducible on original commit 447db0046f21df411c817f9f05b9f6210adb9d81 testing commit 447db0046f21df411c817f9f05b9f6210adb9d81 gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.44 kernel signature: 7a07ed8fb4f48bf5620de67b921ff425f111096e6e9b136890ace345bdea62c1 all runs: crashed: KASAN: use-after-free Read in check_tty_count representative crash: KASAN: use-after-free Read in check_tty_count, types: [KASAN-USE-AFTER-FREE-READ] check whether we can drop unnecessary instrumentation disabling configs for [hang memleak ubsan bug_or_warning locking atomic_sleep], they are not needed testing commit 447db0046f21df411c817f9f05b9f6210adb9d81 gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.44 kernel signature: cc2c7b8c83fb480730e834c5628200795691bba47bfcb6dcd00194dd963d42f4 run #0: crashed: KASAN: use-after-free Read in check_tty_count run #1: crashed: KASAN: use-after-free Read in check_tty_count run #2: crashed: KASAN: use-after-free Read in check_tty_count run #3: crashed: KASAN: use-after-free Read in tty_open run #4: crashed: KASAN: use-after-free Read in check_tty_count run #5: crashed: KASAN: use-after-free Read in check_tty_count run #6: crashed: KASAN: use-after-free Read in check_tty_count run #7: crashed: KASAN: use-after-free Read in check_tty_count run #8: crashed: KASAN: use-after-free Read in check_tty_count run #9: crashed: KASAN: use-after-free Read in check_tty_count representative crash: KASAN: use-after-free Read in check_tty_count, types: [KASAN-USE-AFTER-FREE-READ] the bug reproduces without the instrumentation disabling configs for [hang memleak ubsan bug_or_warning locking atomic_sleep], they are not needed kconfig minimization: base=4788 full=6024 leaves diff=248 split chunks (needed=false): <248> split chunk #0 of len 248 into 5 parts testing without sub-chunk 1/5 disabling configs for [bug_or_warning locking atomic_sleep hang memleak ubsan], they are not needed testing commit 447db0046f21df411c817f9f05b9f6210adb9d81 gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.44 kernel signature: 3997de6eeeb8fed50b52fa4c4b9af61e65dff9486d8016771e253b609ecd1e5e run #0: crashed: KASAN: use-after-free Read in check_tty_count run #1: crashed: KASAN: use-after-free Read in check_tty_count run #2: crashed: KASAN: use-after-free Read in check_tty_count run #3: crashed: KASAN: use-after-free Read in check_tty_count run #4: crashed: KASAN: use-after-free Read in check_tty_count run #5: crashed: KASAN: use-after-free Read in check_tty_count run #6: crashed: KASAN: use-after-free Read in check_tty_count run #7: crashed: KASAN: use-after-free Read in check_tty_count run #8: crashed: KASAN: use-after-free Read in check_tty_count run #9: crashed: KASAN: use-after-free Read in tty_open representative crash: KASAN: use-after-free Read in check_tty_count, types: [KASAN-USE-AFTER-FREE-READ] the chunk can be dropped testing without sub-chunk 2/5 disabling configs for [locking atomic_sleep hang memleak ubsan bug_or_warning], they are not needed testing commit 447db0046f21df411c817f9f05b9f6210adb9d81 gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.44 kernel signature: 1518659ac4c165db3287940341d9c0f41ff64a7099619198d57645ed4d952d38 all runs: crashed: KASAN: use-after-free Read in check_tty_count representative crash: KASAN: use-after-free Read in check_tty_count, types: [KASAN-USE-AFTER-FREE-READ] the chunk can be dropped testing without sub-chunk 3/5 disabling configs for [atomic_sleep hang memleak ubsan bug_or_warning locking], they are not needed testing commit 447db0046f21df411c817f9f05b9f6210adb9d81 gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.44 kernel signature: c7116373fc88ec069824cb0fce42d66a2185b3ed020abab106db8d2deba75f14 all runs: OK false negative chance: 0.000 testing without sub-chunk 4/5 disabling configs for [hang memleak ubsan bug_or_warning locking atomic_sleep], they are not needed testing commit 447db0046f21df411c817f9f05b9f6210adb9d81 gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.44 kernel signature: c986385831b1c512a4b13fe06f8dcb9c2ce903f599c078425369d58e2457ccec run #0: crashed: KASAN: use-after-free Read in check_tty_count run #1: crashed: KASAN: use-after-free Read in check_tty_count run #2: crashed: KASAN: use-after-free Read in check_tty_count run #3: crashed: KASAN: use-after-free Read in tty_open run #4: crashed: KASAN: use-after-free Read in check_tty_count run #5: crashed: KASAN: use-after-free Read in check_tty_count run #6: crashed: KASAN: use-after-free Read in check_tty_count run #7: crashed: KASAN: use-after-free Read in check_tty_count run #8: crashed: KASAN: use-after-free Read in check_tty_count run #9: crashed: KASAN: use-after-free Write in release_tty representative crash: KASAN: use-after-free Read in check_tty_count, types: [KASAN-USE-AFTER-FREE-READ] the chunk can be dropped testing without sub-chunk 5/5 disabling configs for [ubsan bug_or_warning locking atomic_sleep hang memleak], they are not needed testing commit 447db0046f21df411c817f9f05b9f6210adb9d81 gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.44 failed building 447db0046f21df411c817f9f05b9f6210adb9d81: net/socket.c:1129:(.text+0x1307): undefined reference to `wext_handle_ioctl' net/socket.c:3398:(.text+0x17c7): undefined reference to `compat_wext_handle_ioctl' net/core/net-procfs.c:346:(.text+0x33b): undefined reference to `wext_proc_exit' net/core/net-procfs.c:330:(.text+0x4e2): undefined reference to `wext_proc_init' minimized to 98 configs; suspects: [HID_SMARTJOYPLUS HID_THRUSTMASTER HID_ZEROPLUS INPUT_TABLET INPUT_TOUCHSCREEN REGMAP_SPI RESET_CONTROLLER RFKILL RFKILL_LEDS RMI4_2D_SENSOR RMI4_CORE RMI4_F03 RMI4_F03_SERIO RMI4_F11 RMI4_F12 RMI4_F30 SMARTJOYPLUS_FF SMSC_PHY SND SND_COMPRESS_OFFLOAD SND_DMAENGINE_PCM SND_DMA_SGBUF SND_DYNAMIC_MINORS SND_HRTIMER SND_HWDEP SND_PCI SND_PCM SND_PCM_TIMER SND_PROC_FS SND_RAWMIDI SND_SOC SND_SOC_ACPI SND_SOC_ACPI_INTEL_MATCH SND_SOC_COMPRESS SND_SOC_GENERIC_DMAENGINE_PCM SND_SOC_I2C_AND_SPI SND_SOC_INTEL_MACH SND_SOC_INTEL_SST_TOPLEVEL SND_SOC_TOPOLOGY SND_SPI SND_SST_ATOM_HIFI2_PLATFORM SND_SST_ATOM_HIFI2_PLATFORM_ACPI SND_TIMER SND_USB SND_USB_AUDIO SND_USB_AUDIO_USE_MEDIA_CONTROLLER SND_VERBOSE_PROCFS SND_X86 SOUND SURFACE_PLATFORMS TABLET_USB_ACECAD TABLET_USB_AIPTEK TABLET_USB_GTCO TABLET_USB_HANWANG TABLET_USB_KBTAB THRUSTMASTER_FF TOOLS_SUPPORT_RELR TOUCHSCREEN_PROPERTIES TYPEC_DP_ALTMODE TYPEC_FUSB302 USB_ARMLINUX USB_BELKIN USB_CONFIGFS USB_CONFIGFS_ACM USB_CONFIGFS_ECM USB_NET_CDC_SUBSET USB_NET_CDC_SUBSET_ENABLE USB_NET_DM9601 USB_NET_GL620A USB_NET_MCS7830 USB_NET_NET1080 USB_NET_PLUSB USB_NET_RNDIS_HOST USB_NET_SMSC75XX USB_NET_SMSC95XX USB_NET_SR9700 USB_NET_SR9800 USB_NET_ZAURUS USB_OHCI_HCD USB_OHCI_HCD_PCI USB_OHCI_HCD_PLATFORM USB_OTG USB_OTG_FSM USB_PRINTER USB_SERIAL USB_SERIAL_FTDI_SIO USB_SERIAL_GENERIC USB_SERIAL_PL2303 USB_STORAGE_ALAUDA USB_STORAGE_CYPRESS_ATACB USB_STORAGE_DATAFAB USB_STORAGE_FREECOM USB_STORAGE_ISD200 USB_STORAGE_JUMPSHOT USB_STORAGE_KARMA USB_STORAGE_ONETOUCH USB_STORAGE_SDDR09 USB_STORAGE_SDDR55 USB_STORAGE_USBAT USB_TRANCEVIBRATOR USB_U_AUDIO USB_U_ETHER USB_U_SERIAL USB_WDM USB_XHCI_PCI_RENESAS WLAN WLAN_VENDOR_ATH WLAN_VENDOR_ATMEL WLAN_VENDOR_BROADCOM WLAN_VENDOR_INTERSIL WLAN_VENDOR_MARVELL WLAN_VENDOR_MEDIATEK WLAN_VENDOR_MICROCHIP WLAN_VENDOR_RALINK WLAN_VENDOR_REALTEK WLAN_VENDOR_RSI WLAN_VENDOR_ZYDAS ZEROPLUS_FF] disabling configs for [atomic_sleep hang memleak ubsan bug_or_warning locking], they are not needed testing current HEAD c5d8ec7afea29a23d30a8110d48bbb586c1c275a testing commit c5d8ec7afea29a23d30a8110d48bbb586c1c275a gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.44 kernel signature: a32197a1558e353ab8d125273b89070325392055a6154abba28401ccb275c597 run #0: crashed: KASAN: use-after-free Read in check_tty_count run #1: crashed: KASAN: use-after-free Read in check_tty_count run #2: crashed: KASAN: use-after-free Read in check_tty_count run #3: crashed: KASAN: use-after-free Read in tty_open run #4: crashed: KASAN: use-after-free Read in tty_open run #5: crashed: KASAN: use-after-free Read in tty_open run #6: crashed: KASAN: use-after-free Read in check_tty_count run #7: crashed: KASAN: use-after-free Read in tty_open run #8: crashed: KASAN: use-after-free Read in check_tty_count run #9: crashed: KASAN: use-after-free Read in tty_open representative crash: KASAN: use-after-free Read in check_tty_count, types: [KASAN-USE-AFTER-FREE-READ] crash still not fixed/happens on the oldest tested release revisions tested: 7, total time: 1h57m13.737197524s (build: 18m3.861726546s, test: 1h20m35.222724156s) crash still not fixed or there were kernel test errors commit msg: Merge android13-5.10 into android13-5.10-lts crash: KASAN: use-after-free Read in check_tty_count ================================================================== BUG: KASAN: use-after-free in instrument_atomic_read include/linux/instrumented.h:71 [inline] BUG: KASAN: use-after-free in test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline] BUG: KASAN: use-after-free in tty_port_kopened include/linux/tty.h:616 [inline] BUG: KASAN: use-after-free in check_tty_count.isra.0+0x119/0x260 drivers/tty/tty_io.c:295 Read of size 8 at addr ffff888115468910 by task syz.5.20/504 CPU: 1 PID: 504 Comm: syz.5.20 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack_lvl+0x81/0xac lib/dump_stack.c:118 print_address_description.constprop.0+0x24/0x160 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:435 [inline] kasan_report.cold+0x82/0xdb mm/kasan/report.c:452 check_region_inline mm/kasan/generic.c:183 [inline] kasan_check_range+0x148/0x190 mm/kasan/generic.c:189 __kasan_check_read+0x11/0x20 mm/kasan/shadow.c:31 instrument_atomic_read include/linux/instrumented.h:71 [inline] test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline] tty_port_kopened include/linux/tty.h:616 [inline] check_tty_count.isra.0+0x119/0x260 drivers/tty/tty_io.c:295 tty_release+0xa0/0xd40 drivers/tty/tty_io.c:1747 __fput+0x237/0x760 fs/file_table.c:281 ____fput+0x9/0x10 fs/file_table.c:314 task_work_run+0xc2/0x140 kernel/task_work.c:189 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_user_mode_loop kernel/entry/common.c:172 [inline] exit_to_user_mode_prepare+0x150/0x160 kernel/entry/common.c:199 syscall_exit_to_user_mode+0x27/0x160 kernel/entry/common.c:274 do_syscall_64+0x3f/0x50 arch/x86/entry/common.c:56 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7fdca5dd20d9 Code: ff 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 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fff2ba51078 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007fdca605bda0 RCX: 00007fdca5dd20d9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007fdca605bda0 R08: 00007fdca605a038 R09: 0000000000000000 R10: 000000000003fda0 R11: 0000000000000246 R12: 00000000000089a3 R13: 00007fdca6059fac R14: 000000000000869b R15: 00007fff2ba51180 Allocated by task 505: kasan_save_stack+0x26/0x50 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:430 [inline] ____kasan_kmalloc mm/kasan/common.c:509 [inline] ____kasan_kmalloc mm/kasan/common.c:468 [inline] __kasan_kmalloc+0xae/0xe0 mm/kasan/common.c:518 kasan_kmalloc include/linux/kasan.h:254 [inline] kmem_cache_alloc_trace+0xa9/0x500 mm/slub.c:2979 kmalloc include/linux/slab.h:555 [inline] kzalloc include/linux/slab.h:667 [inline] gs_port_alloc drivers/usb/gadget/function/u_serial.c:1162 [inline] gserial_alloc_line_no_console+0x86/0x620 drivers/usb/gadget/function/u_serial.c:1242 gserial_alloc_line+0x9/0x10 drivers/usb/gadget/function/u_serial.c:1276 acm_alloc_instance+0x83/0xe0 drivers/usb/gadget/function/f_acm.c:849 try_get_usb_function_instance+0xee/0x190 drivers/usb/gadget/functions.c:28 usb_get_function_instance+0xe/0x50 drivers/usb/gadget/functions.c:44 function_make+0xf6/0x410 drivers/usb/gadget/configfs.c:636 configfs_mkdir+0x485/0x1090 fs/configfs/dir.c:1382 vfs_mkdir+0x463/0x700 fs/namei.c:3840 do_mkdirat+0x12a/0x290 fs/namei.c:3862 __do_sys_mkdirat fs/namei.c:3873 [inline] __se_sys_mkdirat fs/namei.c:3871 [inline] __x64_sys_mkdirat+0x71/0xb0 fs/namei.c:3871 do_syscall_64+0x32/0x50 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb Freed by task 505: kasan_save_stack+0x26/0x50 mm/kasan/common.c:38 kasan_set_track+0x25/0x30 mm/kasan/common.c:45 kasan_set_free_info+0x24/0x40 mm/kasan/generic.c:370 ____kasan_slab_free mm/kasan/common.c:362 [inline] ____kasan_slab_free mm/kasan/common.c:324 [inline] __kasan_slab_free+0x111/0x150 mm/kasan/common.c:370 kasan_slab_free include/linux/kasan.h:220 [inline] slab_free_hook mm/slub.c:1600 [inline] slab_free_freelist_hook+0x9b/0x1a0 mm/slub.c:1626 slab_free mm/slub.c:3208 [inline] kfree+0xc2/0x4e0 mm/slub.c:4196 gserial_free_port+0xe6/0x1e0 drivers/usb/gadget/function/u_serial.c:1206 gserial_free_line+0x77/0xb0 drivers/usb/gadget/function/u_serial.c:1223 acm_free_instance+0x39/0x50 drivers/usb/gadget/function/f_acm.c:836 usb_put_function_instance+0x80/0xb0 drivers/usb/gadget/functions.c:77 acm_attr_release+0x9/0x10 drivers/usb/gadget/function/f_acm.c:785 config_item_cleanup+0x122/0x210 fs/configfs/item.c:130 config_item_release fs/configfs/item.c:139 [inline] kref_put include/linux/kref.h:65 [inline] config_item_put+0x45/0x60 fs/configfs/item.c:151 configfs_rmdir+0x731/0x9e0 fs/configfs/dir.c:1608 vfs_rmdir.part.0+0xdf/0x3e0 fs/namei.c:3902 vfs_rmdir fs/namei.c:3888 [inline] do_rmdir+0x2b4/0x3a0 fs/namei.c:3962 __do_sys_rmdir fs/namei.c:3980 [inline] __se_sys_rmdir fs/namei.c:3978 [inline] __x64_sys_rmdir+0xa5/0xe0 fs/namei.c:3978 do_syscall_64+0x32/0x50 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb The buggy address belongs to the object at ffff888115468800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 272 bytes inside of 1024-byte region [ffff888115468800, ffff888115468c00) The buggy address belongs to the page: page:ffffea0004551a00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x115468 head:ffffea0004551a00 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head) raw: 4000000000010200 0000000000000000 0000000100000001 ffff888100042f00 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 96, ts 4188930183, free_ts 0 set_page_owner include/linux/page_owner.h:35 [inline] post_alloc_hook mm/page_alloc.c:2456 [inline] prep_new_page mm/page_alloc.c:2462 [inline] get_page_from_freelist+0x1fee/0x2ad0 mm/page_alloc.c:4254 __alloc_pages_nodemask+0x2ae/0x2540 mm/page_alloc.c:5384 __alloc_pages include/linux/gfp.h:544 [inline] __alloc_pages_node include/linux/gfp.h:557 [inline] alloc_pages_node include/linux/gfp.h:571 [inline] alloc_pages include/linux/gfp.h:590 [inline] alloc_slab_page mm/slub.c:1670 [inline] allocate_slab+0x30f/0x460 mm/slub.c:1813 new_slab mm/slub.c:1874 [inline] new_slab_objects mm/slub.c:2632 [inline] ___slab_alloc.constprop.0+0x32b/0x730 mm/slub.c:2796 __slab_alloc mm/slub.c:2836 [inline] slab_alloc_node mm/slub.c:2918 [inline] slab_alloc mm/slub.c:2960 [inline] __kmalloc_track_caller+0x325/0x360 mm/slub.c:4541 __kmalloc_reserve net/core/skbuff.c:144 [inline] __alloc_skb+0x74/0x4d0 net/core/skbuff.c:212 alloc_skb include/linux/skbuff.h:1126 [inline] netlink_alloc_large_skb net/netlink/af_netlink.c:1178 [inline] netlink_sendmsg+0x8a4/0xd10 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:652 [inline] __sock_sendmsg+0xb5/0xf0 net/socket.c:664 ____sys_sendmsg+0x694/0x990 net/socket.c:2377 ___sys_sendmsg+0xfc/0x190 net/socket.c:2431 __sys_sendmsg+0xc3/0x160 net/socket.c:2460 __do_sys_sendmsg net/socket.c:2469 [inline] __se_sys_sendmsg net/socket.c:2467 [inline] __x64_sys_sendmsg+0x73/0xb0 net/socket.c:2467 do_syscall_64+0x32/0x50 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb page_owner free stack trace missing Memory state around the buggy address: ffff888115468800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888115468880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888115468900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888115468980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888115468a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================