Linux: >> Linux Kernel >> 4.19.303 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
rcu: Protect rcu_print_task_exp_stall() ->exp_tasks access
For kernels built with CONFIG_PREEMPT_RCU=y, the following scenario can
result in a NULL-pointer dereference:
CPU1 CPU2
rcu_preempt_deferred_qs_irqrestore rcu_print_task_exp_stall
if (special.b.blocked) READ_ONCE(rnp->exp_tasks) != NULL
raw_spin_lock_rcu_node
np = rcu_next_node_entry(t, rnp)
if (&t->rcu_node_entry == rnp->exp_tasks)
WRITE_ONCE(rnp->exp_tasks, np)
....
raw_spin_unlock_irqrestore_rcu_node
raw_spin_lock_irqsave_rcu_node
t = list_entry(rnp->exp_tasks->prev,
struct task_struct, rcu_node_entry)
(if rnp->exp_tasks is NULL, this
will dereference a NULL pointer)
The problem is that CPU2 accesses the rcu_node structure's->exp_tasks
field without holding the rcu_node structure's ->lock and CPU2 did
not observe CPU1's change to rcu_node structure's ->exp_tasks in time.
Therefore, if CPU1 sets rcu_node structure's->exp_tasks pointer to NULL,
then CPU2 might dereference that NULL pointer.
This commit therefore holds the rcu_node structure's ->lock while
accessing that structure's->exp_tasks field.
[ paulmck: Apply Frederic Weisbecker feedback. ]
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-18
In the Linux kernel, the following vulnerability has been resolved:
NFSD: Protect against send buffer overflow in NFSv2 READ
Since before the git era, NFSD has conserved the number of pages
held by each nfsd thread by combining the RPC receive and send
buffers into a single array of pages. This works because there are
no cases where an operation needs a large RPC Call message and a
large RPC Reply at the same time.
Once an RPC Call has been received, svc_process() updates
svc_rqst::rq_res to describe the part of rq_pages that can be
used for constructing the Reply. This means that the send buffer
(rq_res) shrinks when the received RPC record containing the RPC
Call is large.
A client can force this shrinkage on TCP by sending a correctly-
formed RPC Call header contained in an RPC record that is
excessively large. The full maximum payload size cannot be
constructed in that case.
CVSS Score
7.8
EPSS Score
0.0
Published
2025-09-18
In the Linux kernel, the following vulnerability has been resolved:
drm: bridge: adv7511: unregister cec i2c device after cec adapter
cec_unregister_adapter() assumes that the underlying adapter ops are
callable. For example, if the CEC adapter currently has a valid physical
address, then the unregistration procedure will invalidate the physical
address by setting it to f.f.f.f. Whence the following kernel oops
observed after removing the adv7511 module:
Unable to handle kernel execution of user memory at virtual address 0000000000000000
Internal error: Oops: 86000004 [#1] PREEMPT_RT SMP
Call trace:
0x0
adv7511_cec_adap_log_addr+0x1ac/0x1c8 [adv7511]
cec_adap_unconfigure+0x44/0x90 [cec]
__cec_s_phys_addr.part.0+0x68/0x230 [cec]
__cec_s_phys_addr+0x40/0x50 [cec]
cec_unregister_adapter+0xb4/0x118 [cec]
adv7511_remove+0x60/0x90 [adv7511]
i2c_device_remove+0x34/0xe0
device_release_driver_internal+0x114/0x1f0
driver_detach+0x54/0xe0
bus_remove_driver+0x60/0xd8
driver_unregister+0x34/0x60
i2c_del_driver+0x2c/0x68
adv7511_exit+0x1c/0x67c [adv7511]
__arm64_sys_delete_module+0x154/0x288
invoke_syscall+0x48/0x100
el0_svc_common.constprop.0+0x48/0xe8
do_el0_svc+0x28/0x88
el0_svc+0x1c/0x50
el0t_64_sync_handler+0xa8/0xb0
el0t_64_sync+0x15c/0x160
Code: bad PC value
---[ end trace 0000000000000000 ]---
Protect against this scenario by unregistering i2c_cec after
unregistering the CEC adapter. Duly disable the CEC clock afterwards
too.
CVSS Score
7.8
EPSS Score
0.0
Published
2025-09-18
In the Linux kernel, the following vulnerability has been resolved:
iomap: iomap: fix memory corruption when recording errors during writeback
Every now and then I see this crash on arm64:
Unable to handle kernel NULL pointer dereference at virtual address 00000000000000f8
Buffer I/O error on dev dm-0, logical block 8733687, async page read
Mem abort info:
ESR = 0x0000000096000006
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x06: level 2 translation fault
Data abort info:
ISV = 0, ISS = 0x00000006
CM = 0, WnR = 0
user pgtable: 64k pages, 42-bit VAs, pgdp=0000000139750000
[00000000000000f8] pgd=0000000000000000, p4d=0000000000000000, pud=0000000000000000, pmd=0000000000000000
Internal error: Oops: 96000006 [#1] PREEMPT SMP
Buffer I/O error on dev dm-0, logical block 8733688, async page read
Dumping ftrace buffer:
Buffer I/O error on dev dm-0, logical block 8733689, async page read
(ftrace buffer empty)
XFS (dm-0): log I/O error -5
Modules linked in: dm_thin_pool dm_persistent_data
XFS (dm-0): Metadata I/O Error (0x1) detected at xfs_trans_read_buf_map+0x1ec/0x590 [xfs] (fs/xfs/xfs_trans_buf.c:296).
dm_bio_prison
XFS (dm-0): Please unmount the filesystem and rectify the problem(s)
XFS (dm-0): xfs_imap_lookup: xfs_ialloc_read_agi() returned error -5, agno 0
dm_bufio dm_log_writes xfs nft_chain_nat xt_REDIRECT nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ip6t_REJECT
potentially unexpected fatal signal 6.
nf_reject_ipv6
potentially unexpected fatal signal 6.
ipt_REJECT nf_reject_ipv4
CPU: 1 PID: 122166 Comm: fsstress Tainted: G W 6.0.0-rc5-djwa #rc5 3004c9f1de887ebae86015f2677638ce51ee7
rpcsec_gss_krb5 auth_rpcgss xt_tcpudp ip_set_hash_ip ip_set_hash_net xt_set nft_compat ip_set_hash_mac ip_set nf_tables
Hardware name: QEMU KVM Virtual Machine, BIOS 1.5.1 06/16/2021
pstate: 60001000 (nZCv daif -PAN -UAO -TCO -DIT +SSBS BTYPE=--)
ip_tables
pc : 000003fd6d7df200
x_tables
lr : 000003fd6d7df1ec
overlay nfsv4
CPU: 0 PID: 54031 Comm: u4:3 Tainted: G W 6.0.0-rc5-djwa #rc5 3004c9f1de887ebae86015f2677638ce51ee7405
Hardware name: QEMU KVM Virtual Machine, BIOS 1.5.1 06/16/2021
Workqueue: writeback wb_workfn
sp : 000003ffd9522fd0
(flush-253:0)
pstate: 60401005 (nZCv daif +PAN -UAO -TCO -DIT +SSBS BTYPE=--)
pc : errseq_set+0x1c/0x100
x29: 000003ffd9522fd0 x28: 0000000000000023 x27: 000002acefeb6780
x26: 0000000000000005 x25: 0000000000000001 x24: 0000000000000000
x23: 00000000ffffffff x22: 0000000000000005
lr : __filemap_set_wb_err+0x24/0xe0
x21: 0000000000000006
sp : fffffe000f80f760
x29: fffffe000f80f760 x28: 0000000000000003 x27: fffffe000f80f9f8
x26: 0000000002523000 x25: 00000000fffffffb x24: fffffe000f80f868
x23: fffffe000f80fbb0 x22: fffffc0180c26a78 x21: 0000000002530000
x20: 0000000000000000 x19: 0000000000000000 x18: 0000000000000000
x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000
x14: 0000000000000001 x13: 0000000000470af3 x12: fffffc0058f70000
x11: 0000000000000040 x10: 0000000000001b20 x9 : fffffe000836b288
x8 : fffffc00eb9fd480 x7 : 0000000000f83659 x6 : 0000000000000000
x5 : 0000000000000869 x4 : 0000000000000005 x3 : 00000000000000f8
x20: 000003fd6d740020 x19: 000000000001dd36 x18: 0000000000000001
x17: 000003fd6d78704c x16: 0000000000000001 x15: 000002acfac87668
x2 : 0000000000000ffa x1 : 00000000fffffffb x0 : 00000000000000f8
Call trace:
errseq_set+0x1c/0x100
__filemap_set_wb_err+0x24/0xe0
iomap_do_writepage+0x5e4/0xd5c
write_cache_pages+0x208/0x674
iomap_writepages+0x34/0x60
xfs_vm_writepages+0x8c/0xcc [xfs 7a861f39c43631f15d3a5884246ba5035d4ca78b]
x14: 0000000000000000 x13: 2064656e72757465 x12: 0000000000002180
x11: 000003fd6d8a82d0 x10: 0000000000000000 x9 : 000003fd6d8ae288
x8 : 0000000000000083 x7 : 00000000ffffffff x6 : 00000000ffffffee
x5 : 00000000fbad2887 x4 : 000003fd6d9abb58 x3 : 000003fd6d740020
x2 : 0000000000000006 x1 : 000000000001dd36 x0 : 0000000000000000
CPU:
---truncated---
CVSS Score
7.8
EPSS Score
0.0
Published
2025-09-18
In the Linux kernel, the following vulnerability has been resolved:
USB: dwc3: fix memory leak with using debugfs_lookup()
When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time. To make things simpler, just
call debugfs_lookup_and_remove() instead which handles all of the logic
at once.
Note, the root dentry for the debugfs directory for the device needs to
be saved so we don't have to keep looking it up, which required a bit
more refactoring to properly create and remove it when needed.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-18
In the Linux kernel, the following vulnerability has been resolved:
USB: isp1362: fix memory leak with using debugfs_lookup()
When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time. To make things simpler, just
call debugfs_lookup_and_remove() instead which handles all of the logic
at once.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-18
In the Linux kernel, the following vulnerability has been resolved:
USB: sl811: fix memory leak with using debugfs_lookup()
When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time. To make things simpler, just
call debugfs_lookup_and_remove() instead which handles all of the logic
at once.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-18
In the Linux kernel, the following vulnerability has been resolved:
USB: gadget: lpc32xx_udc: fix memory leak with using debugfs_lookup()
When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time. To make things simpler, just
call debugfs_lookup_and_remove() instead which handles all of the logic
at once.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-18
In the Linux kernel, the following vulnerability has been resolved:
USB: gadget: pxa25x_udc: fix memory leak with using debugfs_lookup()
When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time. To make things simpler, just
call debugfs_lookup_and_remove() instead which handles all of the logic
at once.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-18
In the Linux kernel, the following vulnerability has been resolved:
USB: gadget: pxa27x_udc: fix memory leak with using debugfs_lookup()
When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time. To make things simpler, just
call debugfs_lookup_and_remove() instead which handles all of the logic
at once.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-18