Description
In the Linux kernel, the following vulnerability has been resolved:
nvme: fix cdev lifetime
Sashiko bot reported a potential problem for the cdev lifetime in [0]
- the code there is heavily based on the NVMe code.
Currently the NS head .open and .release file_operations methods take and
put a reference to the nvme_ns_head to ensure that this structure does not
disappear while we open fds for that cdev.
In multipath mode, when we teardown the NS head, we call nvme_cdev_del() ->
cdev_device_del() -> cdev_del(). However after cdev_del() returns, cdevs
already open will remain and their fops will still be callable. As such,
we can still reference the cdev after the nvme_ns_head reference count
drops to 0 (and is freed).
This can be shown with an application which delays between opening the cdev
and issuing the ioctl while the NS head is being torn down:
# ./ioctl_file /dev/ng1n1 &
# waiting 10 seconds ....
# ./ini_nvme_teardown.sh
[ 21.221718] nvme nvme1: Removing ctrl: NQN "nvme-test-target"
[ 21.274609] nvme nvme2: Removing ctrl: NQN "nvme-test-target"
# now going to issue ioctl ....
[ 26.549285] ==================================================================
[ 26.550841] BUG: KASAN: slab-use-after-free in cdev_put.part.0+0x3d/0x40
[ 26.552352] Read of size 8 at addr ffff88811e7fa170 by task ioctl_file/237
[ 26.553805]
[ 26.554227] CPU: 3 UID: 0 PID: 237 Comm: ioctl_file Not tainted 7.2.0-rc1-00004-g6852a10e32d4 #921 PREEMPT(lazy)
[ 26.554236] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[ 26.554241] Call Trace:
[ 26.554245] <TASK>
[ 26.554248] dump_stack_lvl+0x68/0xa0
[ 26.554266] print_report+0x10d/0x5d0
[ 26.554276] ? __virt_addr_valid+0x21d/0x3f0
[ 26.554287] ? cdev_put.part.0+0x3d/0x40
[ 26.554292] kasan_report+0x96/0xd0
[ 26.554300] ? cdev_put.part.0+0x3d/0x40
[ 26.554307] cdev_put.part.0+0x3d/0x40
[ 26.554313] __fput+0x7bc/0xa70
[ 26.554322] fput_close_sync+0xd8/0x190
[ 26.554328] ? __pfx_fput_close_sync+0x10/0x10
[ 26.554337] __x64_sys_close+0x79/0xd0
[ 26.554344] do_syscall_64+0x117/0x6b0
[ 26.554351] entry_SYSCALL_64_after_hwframe+0x77/0x7f
[ 26.554358] RIP: 0033:0x7f938c067727
[ 26.554364] Code: 48 89 fa 4c 89 df e8 28 ad 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5bf
[ 26.554369] RSP: 002b:00007fff49f05980 EFLAGS: 00000202 ORIG_RAX: 0000000000000003
[ 26.554376] RAX: ffffffffffffffda RBX: 00007f938bfd7780 RCX: 00007f938c067727
[ 26.554380] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
[ 26.554383] RBP: 00007fff49f05a10 R08: 0000000000000000 R09: 0000000000000000
[ 26.554386] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
[ 26.554389] R13: 00007fff49f05b40 R14: 00007f938c207000 R15: 000055c148471d78
[ 26.554397] </TASK>
[ 26.554399]
[ 26.575612] Allocated by task 100:
[ 26.575871] kasan_save_stack+0x24/0x50
[ 26.576157] kasan_save_track+0x14/0x30
[ 26.576418] __kasan_kmalloc+0x7f/0x90
[ 26.576668] __kmalloc_noprof+0x281/0x6c0
[ 26.576938] nvme_alloc_ns+0x7f7/0x3170
[ 26.577206] nvme_scan_ns+0x508/0x880
[ 26.577449] async_run_entry_fn+0x8c/0x350
[ 26.577723] process_scheduled_works+0xb6f/0x1a00
[ 26.578034] worker_thread+0x4ad/0xb40
[ 26.578283] kthread+0x34f/0x450
[ 26.578501] ret_from_fork+0x563/0x800
[ 26.578752] ret_from_fork_asm+0x1a/0x30
[ 26.579012]
[ 26.579124] Freed by task 237:
[ 26.579335] kasan_save_stack+0x24/0x50
[ 26.579596] kasan_save_track+0x14/0x30
[ 26.579855] kasan_save_free_info+0x3a/0x60
[ 26.580131] __kasan_slab_free+0x43/0x70
[ 26.580388] kfree+0x321/0x500
[ 26.580591] nvme_ns_head_chr_release+0x39/0x50
[ 26.580883] __fput+0x352/0xa70
[ 26.581095] fput_close_sync+0xd8/0x190
[ 26.581350] __x64_sys_close+0x79/0xd0
[ 26.581595] do_syscall_64+0x117/0x6b0
[ 26.581842] entry_SYSCAL
---truncated---
nvme: fix cdev lifetime
Sashiko bot reported a potential problem for the cdev lifetime in [0]
- the code there is heavily based on the NVMe code.
Currently the NS head .open and .release file_operations methods take and
put a reference to the nvme_ns_head to ensure that this structure does not
disappear while we open fds for that cdev.
In multipath mode, when we teardown the NS head, we call nvme_cdev_del() ->
cdev_device_del() -> cdev_del(). However after cdev_del() returns, cdevs
already open will remain and their fops will still be callable. As such,
we can still reference the cdev after the nvme_ns_head reference count
drops to 0 (and is freed).
This can be shown with an application which delays between opening the cdev
and issuing the ioctl while the NS head is being torn down:
# ./ioctl_file /dev/ng1n1 &
# waiting 10 seconds ....
# ./ini_nvme_teardown.sh
[ 21.221718] nvme nvme1: Removing ctrl: NQN "nvme-test-target"
[ 21.274609] nvme nvme2: Removing ctrl: NQN "nvme-test-target"
# now going to issue ioctl ....
[ 26.549285] ==================================================================
[ 26.550841] BUG: KASAN: slab-use-after-free in cdev_put.part.0+0x3d/0x40
[ 26.552352] Read of size 8 at addr ffff88811e7fa170 by task ioctl_file/237
[ 26.553805]
[ 26.554227] CPU: 3 UID: 0 PID: 237 Comm: ioctl_file Not tainted 7.2.0-rc1-00004-g6852a10e32d4 #921 PREEMPT(lazy)
[ 26.554236] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[ 26.554241] Call Trace:
[ 26.554245] <TASK>
[ 26.554248] dump_stack_lvl+0x68/0xa0
[ 26.554266] print_report+0x10d/0x5d0
[ 26.554276] ? __virt_addr_valid+0x21d/0x3f0
[ 26.554287] ? cdev_put.part.0+0x3d/0x40
[ 26.554292] kasan_report+0x96/0xd0
[ 26.554300] ? cdev_put.part.0+0x3d/0x40
[ 26.554307] cdev_put.part.0+0x3d/0x40
[ 26.554313] __fput+0x7bc/0xa70
[ 26.554322] fput_close_sync+0xd8/0x190
[ 26.554328] ? __pfx_fput_close_sync+0x10/0x10
[ 26.554337] __x64_sys_close+0x79/0xd0
[ 26.554344] do_syscall_64+0x117/0x6b0
[ 26.554351] entry_SYSCALL_64_after_hwframe+0x77/0x7f
[ 26.554358] RIP: 0033:0x7f938c067727
[ 26.554364] Code: 48 89 fa 4c 89 df e8 28 ad 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5bf
[ 26.554369] RSP: 002b:00007fff49f05980 EFLAGS: 00000202 ORIG_RAX: 0000000000000003
[ 26.554376] RAX: ffffffffffffffda RBX: 00007f938bfd7780 RCX: 00007f938c067727
[ 26.554380] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
[ 26.554383] RBP: 00007fff49f05a10 R08: 0000000000000000 R09: 0000000000000000
[ 26.554386] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
[ 26.554389] R13: 00007fff49f05b40 R14: 00007f938c207000 R15: 000055c148471d78
[ 26.554397] </TASK>
[ 26.554399]
[ 26.575612] Allocated by task 100:
[ 26.575871] kasan_save_stack+0x24/0x50
[ 26.576157] kasan_save_track+0x14/0x30
[ 26.576418] __kasan_kmalloc+0x7f/0x90
[ 26.576668] __kmalloc_noprof+0x281/0x6c0
[ 26.576938] nvme_alloc_ns+0x7f7/0x3170
[ 26.577206] nvme_scan_ns+0x508/0x880
[ 26.577449] async_run_entry_fn+0x8c/0x350
[ 26.577723] process_scheduled_works+0xb6f/0x1a00
[ 26.578034] worker_thread+0x4ad/0xb40
[ 26.578283] kthread+0x34f/0x450
[ 26.578501] ret_from_fork+0x563/0x800
[ 26.578752] ret_from_fork_asm+0x1a/0x30
[ 26.579012]
[ 26.579124] Freed by task 237:
[ 26.579335] kasan_save_stack+0x24/0x50
[ 26.579596] kasan_save_track+0x14/0x30
[ 26.579855] kasan_save_free_info+0x3a/0x60
[ 26.580131] __kasan_slab_free+0x43/0x70
[ 26.580388] kfree+0x321/0x500
[ 26.580591] nvme_ns_head_chr_release+0x39/0x50
[ 26.580883] __fput+0x352/0xa70
[ 26.581095] fput_close_sync+0xd8/0x190
[ 26.581350] __x64_sys_close+0x79/0xd0
[ 26.581595] do_syscall_64+0x117/0x6b0
[ 26.581842] entry_SYSCAL
---truncated---
Published:
2026-10-18
Score:
n/a
EPSS:
n/a
KEV:
No
Impact:
n/a
Action:
n/a
Analysis
Analysis and contextual insights are available on OpenCVE Cloud.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux | unaffected |
|
||||||||||||
| Linux | Linux | affected |
|
No data.
No data.
No data available yet.
Remediation
No vendor fix or workaround currently provided.
Additional remediation guidance may be available on OpenCVE Cloud.
Tracking
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Advisories
No advisories yet.
References
History
Sun, 18 Oct 2026 16:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: nvme: fix cdev lifetime Sashiko bot reported a potential problem for the cdev lifetime in [0] - the code there is heavily based on the NVMe code. Currently the NS head .open and .release file_operations methods take and put a reference to the nvme_ns_head to ensure that this structure does not disappear while we open fds for that cdev. In multipath mode, when we teardown the NS head, we call nvme_cdev_del() -> cdev_device_del() -> cdev_del(). However after cdev_del() returns, cdevs already open will remain and their fops will still be callable. As such, we can still reference the cdev after the nvme_ns_head reference count drops to 0 (and is freed). This can be shown with an application which delays between opening the cdev and issuing the ioctl while the NS head is being torn down: # ./ioctl_file /dev/ng1n1 & # waiting 10 seconds .... # ./ini_nvme_teardown.sh [ 21.221718] nvme nvme1: Removing ctrl: NQN "nvme-test-target" [ 21.274609] nvme nvme2: Removing ctrl: NQN "nvme-test-target" # now going to issue ioctl .... [ 26.549285] ================================================================== [ 26.550841] BUG: KASAN: slab-use-after-free in cdev_put.part.0+0x3d/0x40 [ 26.552352] Read of size 8 at addr ffff88811e7fa170 by task ioctl_file/237 [ 26.553805] [ 26.554227] CPU: 3 UID: 0 PID: 237 Comm: ioctl_file Not tainted 7.2.0-rc1-00004-g6852a10e32d4 #921 PREEMPT(lazy) [ 26.554236] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 26.554241] Call Trace: [ 26.554245] <TASK> [ 26.554248] dump_stack_lvl+0x68/0xa0 [ 26.554266] print_report+0x10d/0x5d0 [ 26.554276] ? __virt_addr_valid+0x21d/0x3f0 [ 26.554287] ? cdev_put.part.0+0x3d/0x40 [ 26.554292] kasan_report+0x96/0xd0 [ 26.554300] ? cdev_put.part.0+0x3d/0x40 [ 26.554307] cdev_put.part.0+0x3d/0x40 [ 26.554313] __fput+0x7bc/0xa70 [ 26.554322] fput_close_sync+0xd8/0x190 [ 26.554328] ? __pfx_fput_close_sync+0x10/0x10 [ 26.554337] __x64_sys_close+0x79/0xd0 [ 26.554344] do_syscall_64+0x117/0x6b0 [ 26.554351] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 26.554358] RIP: 0033:0x7f938c067727 [ 26.554364] Code: 48 89 fa 4c 89 df e8 28 ad 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5bf [ 26.554369] RSP: 002b:00007fff49f05980 EFLAGS: 00000202 ORIG_RAX: 0000000000000003 [ 26.554376] RAX: ffffffffffffffda RBX: 00007f938bfd7780 RCX: 00007f938c067727 [ 26.554380] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 [ 26.554383] RBP: 00007fff49f05a10 R08: 0000000000000000 R09: 0000000000000000 [ 26.554386] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 [ 26.554389] R13: 00007fff49f05b40 R14: 00007f938c207000 R15: 000055c148471d78 [ 26.554397] </TASK> [ 26.554399] [ 26.575612] Allocated by task 100: [ 26.575871] kasan_save_stack+0x24/0x50 [ 26.576157] kasan_save_track+0x14/0x30 [ 26.576418] __kasan_kmalloc+0x7f/0x90 [ 26.576668] __kmalloc_noprof+0x281/0x6c0 [ 26.576938] nvme_alloc_ns+0x7f7/0x3170 [ 26.577206] nvme_scan_ns+0x508/0x880 [ 26.577449] async_run_entry_fn+0x8c/0x350 [ 26.577723] process_scheduled_works+0xb6f/0x1a00 [ 26.578034] worker_thread+0x4ad/0xb40 [ 26.578283] kthread+0x34f/0x450 [ 26.578501] ret_from_fork+0x563/0x800 [ 26.578752] ret_from_fork_asm+0x1a/0x30 [ 26.579012] [ 26.579124] Freed by task 237: [ 26.579335] kasan_save_stack+0x24/0x50 [ 26.579596] kasan_save_track+0x14/0x30 [ 26.579855] kasan_save_free_info+0x3a/0x60 [ 26.580131] __kasan_slab_free+0x43/0x70 [ 26.580388] kfree+0x321/0x500 [ 26.580591] nvme_ns_head_chr_release+0x39/0x50 [ 26.580883] __fput+0x352/0xa70 [ 26.581095] fput_close_sync+0xd8/0x190 [ 26.581350] __x64_sys_close+0x79/0xd0 [ 26.581595] do_syscall_64+0x117/0x6b0 [ 26.581842] entry_SYSCAL ---truncated--- | |
| Title | nvme: fix cdev lifetime | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-10-18T15:49:03.248Z
Reserved: 2026-09-25T10:25:14.371Z
Link: CVE-2026-98815
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-10-18T16:17:35.640
Modified: 2026-10-18T16:17:35.640
Link: CVE-2026-98815
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.