[syzbot] [usb?] memory leak in hub_event (4)

syzbot
2026-04-25T02:12:43Z

Hello,

syzbot found the following issue on:

HEAD commit: dd6c438c3e64 Merge tag 'vfs-7.1-rc1.fixes' of git://git.ke..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=15cf7702580000
kernel config: https://syzkaller.appspot.com/x/.config?x=ac5083db84233db3
dashboard link: https://syzkaller.appspot.com/bug?extid=2afd7e71155c7e241560
compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=13cf7702580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17941c36580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/dea6ab846ab3/disk-dd6c438c.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/acebe380aa03/vmlinux-dd6c438c.xz
kernel image: https://storage.googleapis.com/syzbot-assets/2cdbd012d0d3/bzImage-dd6c438c.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+2afd7e71155c7e241560@syzkaller.appspotmail.com

BUG: memory leak
unreferenced object 0xffff8881277dc000 (size 2048):
comm "kworker/0:2", pid 1783, jiffies 4294946784
hex dump (first 32 bytes):
ff ff ff ff 31 00 00 00 00 00 00 00 00 00 00 00 ....1...........
00 00 00 00 00 00 00 00 00 00 00 00 02 00 00 00 ................
backtrace (crc 20105372):
kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
slab_post_alloc_hook mm/slub.c:4574 [inline]
slab_alloc_node mm/slub.c:4898 [inline]
__kmalloc_cache_noprof+0x371/0x480 mm/slub.c:5410
kmalloc_noprof include/linux/slab.h:950 [inline]
kzalloc_noprof include/linux/slab.h:1188 [inline]
usb_alloc_dev+0x36/0x4e0 drivers/usb/core/usb.c:651
hub_port_connect drivers/usb/core/hub.c:5470 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
port_event drivers/usb/core/hub.c:5871 [inline]
hub_event+0x14d0/0x2180 drivers/usb/core/hub.c:5953
process_one_work+0x277/0x5b0 kernel/workqueue.c:3302
process_scheduled_works kernel/workqueue.c:3385 [inline]
worker_thread+0x255/0x4a0 kernel/workqueue.c:3466
kthread+0x14e/0x1a0 kernel/kthread.c:436
ret_from_fork+0x219/0x490 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

BUG: memory leak
unreferenced object 0xffff888128b06c00 (size 1024):
comm "kworker/0:2", pid 1783, jiffies 4294946815
hex dump (first 32 bytes):
09 02 49 00 02 01 00 10 40 00 00 00 00 00 00 00 ..I.....@.......
00 00 00 00 00 00 00 00 89 b8 69 09 81 88 ff ff ..........i.....
backtrace (crc b43c3ef8):
kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
slab_post_alloc_hook mm/slub.c:4574 [inline]
slab_alloc_node mm/slub.c:4898 [inline]
__do_kmalloc_node mm/slub.c:5294 [inline]
__kmalloc_noprof+0x3b7/0x550 mm/slub.c:5307
kmalloc_noprof include/linux/slab.h:954 [inline]
kzalloc_noprof include/linux/slab.h:1188 [inline]
usb_get_configuration+0xeb/0x2110 drivers/usb/core/config.c:940
usb_enumerate_device drivers/usb/core/hub.c:2527 [inline]
usb_new_device+0x1b4/0x300 drivers/usb/core/hub.c:2665
hub_port_connect drivers/usb/core/hub.c:5567 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
port_event drivers/usb/core/hub.c:5871 [inline]
hub_event+0x1723/0x2180 drivers/usb/core/hub.c:5953
process_one_work+0x277/0x5b0 kernel/workqueue.c:3302
process_scheduled_works kernel/workqueue.c:3385 [inline]
worker_thread+0x255/0x4a0 kernel/workqueue.c:3466
kthread+0x14e/0x1a0 kernel/kthread.c:436
ret_from_fork+0x219/0x490 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

BUG: memory leak
unreferenced object 0xffff88810c3d5a50 (size 8):
comm "kworker/0:2", pid 1783, jiffies 4294946815
hex dump (first 8 bytes):
80 b8 69 09 81 88 ff ff ..i.....
backtrace (crc 66af3167):
kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
slab_post_alloc_hook mm/slub.c:4574 [inline]
slab_alloc_node mm/slub.c:4898 [inline]
__do_kmalloc_node mm/slub.c:5294 [inline]
__kmalloc_noprof+0x3b7/0x550 mm/slub.c:5307
kmalloc_noprof include/linux/slab.h:954 [inline]
kzalloc_noprof include/linux/slab.h:1188 [inline]
usb_get_configuration+0x11d/0x2110 drivers/usb/core/config.c:945
usb_enumerate_device drivers/usb/core/hub.c:2527 [inline]
usb_new_device+0x1b4/0x300 drivers/usb/core/hub.c:2665
hub_port_connect drivers/usb/core/hub.c:5567 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
port_event drivers/usb/core/hub.c:5871 [inline]
hub_event+0x1723/0x2180 drivers/usb/core/hub.c:5953
process_one_work+0x277/0x5b0 kernel/workqueue.c:3302
process_scheduled_works kernel/workqueue.c:3385 [inline]
worker_thread+0x255/0x4a0 kernel/workqueue.c:3466
kthread+0x14e/0x1a0 kernel/kthread.c:436
ret_from_fork+0x219/0x490 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

BUG: memory leak
unreferenced object 0xffff888113c25840 (size 64):
comm "kworker/0:2", pid 1783, jiffies 4294946817
hex dump (first 32 bytes):
01 00 00 00 01 00 00 00 09 04 00 00 00 01 01 30 ...............0
00 00 00 00 0a 00 00 00 9a b8 69 09 81 88 ff ff ..........i.....
backtrace (crc a90fa323):
kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
slab_post_alloc_hook mm/slub.c:4574 [inline]
slab_alloc_node mm/slub.c:4898 [inline]
__do_kmalloc_node mm/slub.c:5294 [inline]
__kmalloc_noprof+0x3b7/0x550 mm/slub.c:5307
kmalloc_noprof include/linux/slab.h:954 [inline]
kzalloc_noprof include/linux/slab.h:1188 [inline]
usb_parse_configuration drivers/usb/core/config.c:826 [inline]
usb_get_configuration+0x88f/0x2110 drivers/usb/core/config.c:1002
usb_enumerate_device drivers/usb/core/hub.c:2527 [inline]
usb_new_device+0x1b4/0x300 drivers/usb/core/hub.c:2665
hub_port_connect drivers/usb/core/hub.c:5567 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
port_event drivers/usb/core/hub.c:5871 [inline]
hub_event+0x1723/0x2180 drivers/usb/core/hub.c:5953
process_one_work+0x277/0x5b0 kernel/workqueue.c:3302
process_scheduled_works kernel/workqueue.c:3385 [inline]
worker_thread+0x255/0x4a0 kernel/workqueue.c:3466
kthread+0x14e/0x1a0 kernel/kthread.c:436
ret_from_fork+0x219/0x490 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

BUG: memory leak
unreferenced object 0xffff88811d54a500 (size 256):
comm "kworker/0:2", pid 1783, jiffies 4294946821
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 08 a5 54 1d 81 88 ff ff ..........T.....
08 a5 54 1d 81 88 ff ff 20 e7 41 83 ff ff ff ff ..T..... .A.....
backtrace (crc 85d09f91):
kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
slab_post_alloc_hook mm/slub.c:4574 [inline]
slab_alloc_node mm/slub.c:4898 [inline]
__kmalloc_cache_noprof+0x371/0x480 mm/slub.c:5410
kmalloc_noprof include/linux/slab.h:950 [inline]
kzalloc_noprof include/linux/slab.h:1188 [inline]
device_private_init drivers/base/core.c:3536 [inline]
device_add+0x73c/0xc70 drivers/base/core.c:3587
usb_new_device.cold+0x115/0x626 drivers/usb/core/hub.c:2695
hub_port_connect drivers/usb/core/hub.c:5567 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
port_event drivers/usb/core/hub.c:5871 [inline]
hub_event+0x1723/0x2180 drivers/usb/core/hub.c:5953
process_one_work+0x277/0x5b0 kernel/workqueue.c:3302
process_scheduled_works kernel/workqueue.c:3385 [inline]
worker_thread+0x255/0x4a0 kernel/workqueue.c:3466
kthread+0x14e/0x1a0 kernel/kthread.c:436
ret_from_fork+0x219/0x490 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

connection error: failed to recv *flatrpc.ExecutorMessageRawT: EOF

---
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