| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
PCI: Fix use-after-free in pci_bus_release_domain_nr()
Commit c14f7ccc9f5d ("PCI: Assign PCI domain IDs by ida_alloc()")
introduced a use-after-free bug in the bus removal cleanup. The issue was
found with kfence:
[ 19.293351] BUG: KFENCE: use-after-free read in pci_bus_release_domain_nr+0x10/0x70
[ 19.302817] Use-after-free read at 0x000000007f3b80eb (in kfence-#115):
[ 19.309677] pci_bus_release_domain_nr+0x10/0x70
[ 19.309691] dw_pcie_host_deinit+0x28/0x78
[ 19.309702] tegra_pcie_deinit_controller+0x1c/0x38 [pcie_tegra194]
[ 19.309734] tegra_pcie_dw_probe+0x648/0xb28 [pcie_tegra194]
[ 19.309752] platform_probe+0x90/0xd8
...
[ 19.311457] kfence-#115: 0x00000000063a155a-0x00000000ba698da8, size=1072, cache=kmalloc-2k
[ 19.311469] allocated by task 96 on cpu 10 at 19.279323s:
[ 19.311562] __kmem_cache_alloc_node+0x260/0x278
[ 19.311571] kmalloc_trace+0x24/0x30
[ 19.311580] pci_alloc_bus+0x24/0xa0
[ 19.311590] pci_register_host_bridge+0x48/0x4b8
[ 19.311601] pci_scan_root_bus_bridge+0xc0/0xe8
[ 19.311613] pci_host_probe+0x18/0xc0
[ 19.311623] dw_pcie_host_init+0x2c0/0x568
[ 19.311630] tegra_pcie_dw_probe+0x610/0xb28 [pcie_tegra194]
[ 19.311647] platform_probe+0x90/0xd8
...
[ 19.311782] freed by task 96 on cpu 10 at 19.285833s:
[ 19.311799] release_pcibus_dev+0x30/0x40
[ 19.311808] device_release+0x30/0x90
[ 19.311814] kobject_put+0xa8/0x120
[ 19.311832] device_unregister+0x20/0x30
[ 19.311839] pci_remove_bus+0x78/0x88
[ 19.311850] pci_remove_root_bus+0x5c/0x98
[ 19.311860] dw_pcie_host_deinit+0x28/0x78
[ 19.311866] tegra_pcie_deinit_controller+0x1c/0x38 [pcie_tegra194]
[ 19.311883] tegra_pcie_dw_probe+0x648/0xb28 [pcie_tegra194]
[ 19.311900] platform_probe+0x90/0xd8
...
[ 19.313579] CPU: 10 PID: 96 Comm: kworker/u24:2 Not tainted 6.2.0 #4
[ 19.320171] Hardware name: /, BIOS 1.0-d7fb19b 08/10/2022
[ 19.325852] Workqueue: events_unbound deferred_probe_work_func
The stack trace is a bit misleading as dw_pcie_host_deinit() doesn't
directly call pci_bus_release_domain_nr(). The issue turns out to be in
pci_remove_root_bus() which first calls pci_remove_bus() which frees the
struct pci_bus when its struct device is released. Then
pci_bus_release_domain_nr() is called and accesses the freed struct
pci_bus. Reordering these fixes the issue. |
| In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix racy issue under cocurrent smb2 tree disconnect
There is UAF issue under cocurrent smb2 tree disconnect.
This patch introduce TREE_CONN_EXPIRE flags for tcon to avoid cocurrent
access. |
| In the Linux kernel, the following vulnerability has been resolved:
media: bttv: fix use after free error due to btv->timeout timer
There may be some a race condition between timer function
bttv_irq_timeout and bttv_remove. The timer is setup in
probe and there is no timer_delete operation in remove
function. When it hit kfree btv, the function might still be
invoked, which will cause use after free bug.
This bug is found by static analysis, it may be false positive.
Fix it by adding del_timer_sync invoking to the remove function.
cpu0 cpu1
bttv_probe
->timer_setup
->bttv_set_dma
->mod_timer;
bttv_remove
->kfree(btv);
->bttv_irq_timeout
->USE btv |
| In the Linux kernel, the following vulnerability has been resolved:
block, bfq: fix uaf for bfqq in bfq_exit_icq_bfqq
Commit 64dc8c732f5c ("block, bfq: fix possible uaf for 'bfqq->bic'")
will access 'bic->bfqq' in bic_set_bfqq(), however, bfq_exit_icq_bfqq()
can free bfqq first, and then call bic_set_bfqq(), which will cause uaf.
Fix the problem by moving bfq_exit_bfqq() behind bic_set_bfqq(). |
| In the Linux kernel, the following vulnerability has been resolved:
net: dsa: lantiq_gswip: fix use after free in gswip_remove()
of_node_put(priv->ds->slave_mii_bus->dev.of_node) should be
done before mdiobus_free(priv->ds->slave_mii_bus). |
| A use after free issue was addressed with improved memory management. This issue is fixed in iOS 18.3 and iPadOS 18.3, iPadOS 17.7.6, macOS Sequoia 15.3, macOS Sonoma 14.7.5, macOS Ventura 13.7.5, tvOS 18.3, visionOS 2.3, watchOS 11.3. A malicious application may be able to elevate privileges. Apple is aware of a report that this issue may have been actively exploited against versions of iOS before iOS 17.2. |
| In the Linux kernel, the following vulnerability has been resolved:
gpib: fix use-after-free in IO ioctl handlers
The IBRD, IBWRT, IBCMD, and IBWAIT ioctl handlers use a gpib_descriptor
pointer after board->big_gpib_mutex has been released. A concurrent
IBCLOSEDEV ioctl can free the descriptor via close_dev_ioctl() during
this window, causing a use-after-free.
The IO handlers (read_ioctl, write_ioctl, command_ioctl) explicitly
release big_gpib_mutex before calling their handler. wait_ioctl() is
called with big_gpib_mutex held, but ibwait() releases it internally
when wait_mask is non-zero. In all four cases, the descriptor pointer
obtained from handle_to_descriptor() becomes unprotected.
Fix this by introducing a kernel-only descriptor_busy reference count
in struct gpib_descriptor. Each handler atomically increments
descriptor_busy under file_priv->descriptors_mutex before releasing the
lock, and decrements it when done. close_dev_ioctl() checks
descriptor_busy under the same lock and rejects the close with -EBUSY
if the count is non-zero.
A reference count rather than a simple flag is necessary because
multiple handlers can operate on the same descriptor concurrently
(e.g. IBRD and IBWAIT on the same handle from different threads).
A separate counter is needed because io_in_progress can be cleared from
unprivileged userspace via the IBWAIT ioctl (through general_ibstatus()
with set_mask containing CMPL), which would allow an attacker to bypass
a check based solely on io_in_progress. The new descriptor_busy
counter is only modified by the kernel IO paths.
The lock ordering is consistent (big_gpib_mutex -> descriptors_mutex)
and the handlers only hold descriptors_mutex briefly during the lookup,
so there is no deadlock risk and no impact on IO throughput. |
| In the Linux kernel, the following vulnerability has been resolved:
NFS: Fix use-after-free in nfs4_init_client()
KASAN reports a use-after-free when attempting to mount two different
exports through two different NICs that belong to the same server.
Olga was able to hit this with kernels starting somewhere between 5.7
and 5.10, but I traced the patch that introduced the clear_bit() call to
4.13. So something must have changed in the refcounting of the clp
pointer to make this call to nfs_put_client() the very last one. |
| In the Linux kernel, the following vulnerability has been resolved:
RDMA/core: Set send and receive CQ before forwarding to the driver
Preset both receive and send CQ pointers prior to call to the drivers and
overwrite it later again till the mlx4 is going to be changed do not
overwrite ibqp properties.
This change is needed for mlx5, because in case of QP creation failure, it
will go to the path of QP destroy which relies on proper CQ pointers.
BUG: KASAN: use-after-free in create_qp.cold+0x164/0x16e [mlx5_ib]
Write of size 8 at addr ffff8880064c55c0 by task a.out/246
CPU: 0 PID: 246 Comm: a.out Not tainted 5.15.0+ #291
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
Call Trace:
dump_stack_lvl+0x45/0x59
print_address_description.constprop.0+0x1f/0x140
kasan_report.cold+0x83/0xdf
create_qp.cold+0x164/0x16e [mlx5_ib]
mlx5_ib_create_qp+0x358/0x28a0 [mlx5_ib]
create_qp.part.0+0x45b/0x6a0 [ib_core]
ib_create_qp_user+0x97/0x150 [ib_core]
ib_uverbs_handler_UVERBS_METHOD_QP_CREATE+0x92c/0x1250 [ib_uverbs]
ib_uverbs_cmd_verbs+0x1c38/0x3150 [ib_uverbs]
ib_uverbs_ioctl+0x169/0x260 [ib_uverbs]
__x64_sys_ioctl+0x866/0x14d0
do_syscall_64+0x3d/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
Allocated by task 246:
kasan_save_stack+0x1b/0x40
__kasan_kmalloc+0xa4/0xd0
create_qp.part.0+0x92/0x6a0 [ib_core]
ib_create_qp_user+0x97/0x150 [ib_core]
ib_uverbs_handler_UVERBS_METHOD_QP_CREATE+0x92c/0x1250 [ib_uverbs]
ib_uverbs_cmd_verbs+0x1c38/0x3150 [ib_uverbs]
ib_uverbs_ioctl+0x169/0x260 [ib_uverbs]
__x64_sys_ioctl+0x866/0x14d0
do_syscall_64+0x3d/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
Freed by task 246:
kasan_save_stack+0x1b/0x40
kasan_set_track+0x1c/0x30
kasan_set_free_info+0x20/0x30
__kasan_slab_free+0x10c/0x150
slab_free_freelist_hook+0xb4/0x1b0
kfree+0xe7/0x2a0
create_qp.part.0+0x52b/0x6a0 [ib_core]
ib_create_qp_user+0x97/0x150 [ib_core]
ib_uverbs_handler_UVERBS_METHOD_QP_CREATE+0x92c/0x1250 [ib_uverbs]
ib_uverbs_cmd_verbs+0x1c38/0x3150 [ib_uverbs]
ib_uverbs_ioctl+0x169/0x260 [ib_uverbs]
__x64_sys_ioctl+0x866/0x14d0
do_syscall_64+0x3d/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae |
| Use-after-free in the DOM: Networking component. This vulnerability was fixed in Firefox 150.0.2, Firefox ESR 140.10.2, Firefox ESR 115.35.2, Thunderbird 150.0.2, and Thunderbird 140.10.2. |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_conntrack_helper: pass helper to expect cleanup
nf_conntrack_helper_unregister() calls nf_ct_expect_iterate_destroy()
to remove expectations belonging to the helper being unregistered.
However, it passes NULL instead of the helper pointer as the data
argument, so expect_iter_me() never matches any expectation and all
of them survive the cleanup.
After unregister returns, nfnl_cthelper_del() frees the helper
object immediately. Subsequent expectation dumps or packet-driven
init_conntrack() calls then dereference the freed exp->helper,
causing a use-after-free.
Pass the actual helper pointer so expectations referencing it are
properly destroyed before the helper object is freed.
BUG: KASAN: slab-use-after-free in string+0x38f/0x430
Read of size 1 at addr ffff888003b14d20 by task poc/103
Call Trace:
string+0x38f/0x430
vsnprintf+0x3cc/0x1170
seq_printf+0x17a/0x240
exp_seq_show+0x2e5/0x560
seq_read_iter+0x419/0x1280
proc_reg_read+0x1ac/0x270
vfs_read+0x179/0x930
ksys_read+0xef/0x1c0
Freed by task 103:
The buggy address is located 32 bytes inside of
freed 192-byte region [ffff888003b14d00, ffff888003b14dc0) |
| In the Linux kernel, the following vulnerability has been resolved:
usb: usbtmc: Flush anchored URBs in usbtmc_release
When calling usbtmc_release, pending anchored URBs must be flushed or
killed to prevent use-after-free errors (e.g. in the HCD giveback
path). Call usbtmc_draw_down() to allow anchored URBs to be completed. |
| A maliciously crafted PRT file, when parsed through certain Autodesk products, can force a Use-After-Free vulnerability. A malicious actor can leverage this vulnerability to cause a crash, read sensitive data, or execute arbitrary code in the context of the current process. |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: hci_conn: fix potential UAF in set_cig_params_sync
hci_conn lookup and field access must be covered by hdev lock in
set_cig_params_sync, otherwise it's possible it is freed concurrently.
Take hdev lock to prevent hci_conn from being deleted or modified
concurrently. Just RCU lock is not suitable here, as we also want to
avoid "tearing" in the configuration. |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: hci_event: fix potential UAF in hci_le_remote_conn_param_req_evt
hci_conn lookup and field access must be covered by hdev lock in
hci_le_remote_conn_param_req_evt, otherwise it's possible it is freed
concurrently.
Extend the hci_dev_lock critical section to cover all conn usage. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: sockmap: Fix use-after-free of sk->sk_socket in sk_psock_verdict_data_ready().
syzbot reported use-after-free of AF_UNIX socket's sk->sk_socket
in sk_psock_verdict_data_ready(). [0]
In unix_stream_sendmsg(), the peer socket's ->sk_data_ready() is
called after dropping its unix_state_lock().
Although the sender socket holds the peer's refcount, it does not
prevent the peer's sock_orphan(), and the peer's sk_socket might
be freed after one RCU grace period.
Let's fetch the peer's sk->sk_socket and sk->sk_socket->ops under
RCU in sk_psock_verdict_data_ready().
[0]:
BUG: KASAN: slab-use-after-free in sk_psock_verdict_data_ready+0xec/0x590 net/core/skmsg.c:1278
Read of size 8 at addr ffff8880594da860 by task syz.4.1842/11013
CPU: 1 UID: 0 PID: 11013 Comm: syz.4.1842 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
<TASK>
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0xba/0x230 mm/kasan/report.c:482
kasan_report+0x117/0x150 mm/kasan/report.c:595
sk_psock_verdict_data_ready+0xec/0x590 net/core/skmsg.c:1278
unix_stream_sendmsg+0x8a3/0xe80 net/unix/af_unix.c:2482
sock_sendmsg_nosec net/socket.c:721 [inline]
__sock_sendmsg net/socket.c:736 [inline]
____sys_sendmsg+0x972/0x9f0 net/socket.c:2585
___sys_sendmsg+0x2a5/0x360 net/socket.c:2639
__sys_sendmsg net/socket.c:2671 [inline]
__do_sys_sendmsg net/socket.c:2676 [inline]
__se_sys_sendmsg net/socket.c:2674 [inline]
__x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2674
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7facf899c819
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:00007facf9827028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007facf8c15fa0 RCX: 00007facf899c819
RDX: 0000000000000000 RSI: 0000200000000500 RDI: 0000000000000004
RBP: 00007facf8a32c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007facf8c16038 R14: 00007facf8c15fa0 R15: 00007ffd41b01c78
</TASK>
Allocated by task 11013:
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
unpoison_slab_object mm/kasan/common.c:340 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4538 [inline]
slab_alloc_node mm/slub.c:4866 [inline]
kmem_cache_alloc_lru_noprof+0x2b8/0x640 mm/slub.c:4885
sock_alloc_inode+0x28/0xc0 net/socket.c:316
alloc_inode+0x6a/0x1b0 fs/inode.c:347
new_inode_pseudo include/linux/fs.h:3003 [inline]
sock_alloc net/socket.c:631 [inline]
__sock_create+0x12d/0x9d0 net/socket.c:1562
sock_create net/socket.c:1656 [inline]
__sys_socketpair+0x1c4/0x560 net/socket.c:1803
__do_sys_socketpair net/socket.c:1856 [inline]
__se_sys_socketpair net/socket.c:1853 [inline]
__x64_sys_socketpair+0x9b/0xb0 net/socket.c:1853
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Freed by task 15:
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253 [inline]
__kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2685 [inline]
slab_free mm/slub.c:6165 [inline]
kmem_cache_free+0x187/0x630 mm/slub.c:6295
rcu_do_batch kernel/rcu/tree.c:
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
net: macb: fix clk handling on PCI glue driver removal
platform_device_unregister() may still want to use the registered clks
during runtime resume callback.
Note that there is a commit d82d5303c4c5 ("net: macb: fix use after free
on rmmod") that addressed the similar problem of clk vs platform device
unregistration but just moved the bug to another place.
Save the pointers to clks into local variables for reuse after platform
device is unregistered.
BUG: KASAN: use-after-free in clk_prepare+0x5a/0x60
Read of size 8 at addr ffff888104f85e00 by task modprobe/597
CPU: 2 PID: 597 Comm: modprobe Not tainted 6.1.164+ #114
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.1-0-g3208b098f51a-prebuilt.qemu.org 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x8d/0xba
print_report+0x17f/0x496
kasan_report+0xd9/0x180
clk_prepare+0x5a/0x60
macb_runtime_resume+0x13d/0x410 [macb]
pm_generic_runtime_resume+0x97/0xd0
__rpm_callback+0xc8/0x4d0
rpm_callback+0xf6/0x230
rpm_resume+0xeeb/0x1a70
__pm_runtime_resume+0xb4/0x170
bus_remove_device+0x2e3/0x4b0
device_del+0x5b3/0xdc0
platform_device_del+0x4e/0x280
platform_device_unregister+0x11/0x50
pci_device_remove+0xae/0x210
device_remove+0xcb/0x180
device_release_driver_internal+0x529/0x770
driver_detach+0xd4/0x1a0
bus_remove_driver+0x135/0x260
driver_unregister+0x72/0xb0
pci_unregister_driver+0x26/0x220
__do_sys_delete_module+0x32e/0x550
do_syscall_64+0x35/0x80
entry_SYSCALL_64_after_hwframe+0x6e/0xd8
</TASK>
Allocated by task 519:
kasan_save_stack+0x2c/0x50
kasan_set_track+0x21/0x30
__kasan_kmalloc+0x8e/0x90
__clk_register+0x458/0x2890
clk_hw_register+0x1a/0x60
__clk_hw_register_fixed_rate+0x255/0x410
clk_register_fixed_rate+0x3c/0xa0
macb_probe+0x1d8/0x42e [macb_pci]
local_pci_probe+0xd7/0x190
pci_device_probe+0x252/0x600
really_probe+0x255/0x7f0
__driver_probe_device+0x1ee/0x330
driver_probe_device+0x4c/0x1f0
__driver_attach+0x1df/0x4e0
bus_for_each_dev+0x15d/0x1f0
bus_add_driver+0x486/0x5e0
driver_register+0x23a/0x3d0
do_one_initcall+0xfd/0x4d0
do_init_module+0x18b/0x5a0
load_module+0x5663/0x7950
__do_sys_finit_module+0x101/0x180
do_syscall_64+0x35/0x80
entry_SYSCALL_64_after_hwframe+0x6e/0xd8
Freed by task 597:
kasan_save_stack+0x2c/0x50
kasan_set_track+0x21/0x30
kasan_save_free_info+0x2a/0x50
__kasan_slab_free+0x106/0x180
__kmem_cache_free+0xbc/0x320
clk_unregister+0x6de/0x8d0
macb_remove+0x73/0xc0 [macb_pci]
pci_device_remove+0xae/0x210
device_remove+0xcb/0x180
device_release_driver_internal+0x529/0x770
driver_detach+0xd4/0x1a0
bus_remove_driver+0x135/0x260
driver_unregister+0x72/0xb0
pci_unregister_driver+0x26/0x220
__do_sys_delete_module+0x32e/0x550
do_syscall_64+0x35/0x80
entry_SYSCALL_64_after_hwframe+0x6e/0xd8 |
| Use after free in Remote Desktop Client allows an unauthorized attacker to execute code over a network. |
| In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix use-after-free and NULL deref in smb_grant_oplock()
smb_grant_oplock() has two issues in the oplock publication sequence:
1) opinfo is linked into ci->m_op_list (via opinfo_add) before
add_lease_global_list() is called. If add_lease_global_list()
fails (kmalloc returns NULL), the error path frees the opinfo
via __free_opinfo() while it is still linked in ci->m_op_list.
Concurrent m_op_list readers (opinfo_get_list, or direct iteration
in smb_break_all_levII_oplock) dereference the freed node.
2) opinfo->o_fp is assigned after add_lease_global_list() publishes
the opinfo on the global lease list. A concurrent
find_same_lease_key() can walk the lease list and dereference
opinfo->o_fp->f_ci while o_fp is still NULL.
Fix by restructuring the publication sequence to eliminate post-publish
failure:
- Set opinfo->o_fp before any list publication (fixes NULL deref).
- Preallocate lease_table via alloc_lease_table() before opinfo_add()
so add_lease_global_list() becomes infallible after publication.
- Keep the original m_op_list publication order (opinfo_add before
lease list) so concurrent opens via same_client_has_lease() and
opinfo_get_list() still see the in-flight grant.
- Use opinfo_put() instead of __free_opinfo() on err_out so that
the RCU-deferred free path is used.
This also requires splitting add_lease_global_list() to take a
preallocated lease_table and changing its return type from int to void,
since it can no longer fail. |
| In the Linux kernel, the following vulnerability has been resolved:
ext4: fix use-after-free in update_super_work when racing with umount
Commit b98535d09179 ("ext4: fix bug_on in start_this_handle during umount
filesystem") moved ext4_unregister_sysfs() before flushing s_sb_upd_work
to prevent new error work from being queued via /proc/fs/ext4/xx/mb_groups
reads during unmount. However, this introduced a use-after-free because
update_super_work calls ext4_notify_error_sysfs() -> sysfs_notify() which
accesses the kobject's kernfs_node after it has been freed by kobject_del()
in ext4_unregister_sysfs():
update_super_work ext4_put_super
----------------- --------------
ext4_unregister_sysfs(sb)
kobject_del(&sbi->s_kobj)
__kobject_del()
sysfs_remove_dir()
kobj->sd = NULL
sysfs_put(sd)
kernfs_put() // RCU free
ext4_notify_error_sysfs(sbi)
sysfs_notify(&sbi->s_kobj)
kn = kobj->sd // stale pointer
kernfs_get(kn) // UAF on freed kernfs_node
ext4_journal_destroy()
flush_work(&sbi->s_sb_upd_work)
Instead of reordering the teardown sequence, fix this by making
ext4_notify_error_sysfs() detect that sysfs has already been torn down
by checking s_kobj.state_in_sysfs, and skipping the sysfs_notify() call
in that case. A dedicated mutex (s_error_notify_mutex) serializes
ext4_notify_error_sysfs() against kobject_del() in ext4_unregister_sysfs()
to prevent TOCTOU races where the kobject could be deleted between the
state_in_sysfs check and the sysfs_notify() call. |
