In the Linux kernel, the following vulnerability has been resolved:
octeontx2-pf: handle otx2_mbox_get_rsp errors in otx2_common.c
Add error pointer check after calling otx2_mbox_get_rsp().
In the Linux kernel, the following vulnerability has been resolved:
crypto: bcm - add error check in the ahash_hmac_init function
The ahash_init functions may return fails. The ahash_hmac_init should
not return ok when ahash_init returns error. For an example, ahash_init
will return -ENOMEM when allocation memory is error.
In the Linux kernel, the following vulnerability has been resolved:
powerpc/fadump: Move fadump_cma_init to setup_arch() after initmem_init()
During early init CMA_MIN_ALIGNMENT_BYTES can be PAGE_SIZE,
since pageblock_order is still zero and it gets initialized
later during initmem_init() e.g.
setup_arch() -> initmem_init() -> sparse_init() -> set_pageblock_order()
One such use case where this causes issue is -
early_setup() -> early_init_devtree() -> fadump_reserve_mem() -> fadump_cma_init()
This causes CMA memory alignment check to be bypassed in
cma_init_reserved_mem(). Then later cma_activate_area() can hit
a VM_BUG_ON_PAGE(pfn & ((1 << order) - 1)) if the reserved memory
area was not pageblock_order aligned.
Fix it by moving the fadump_cma_init() after initmem_init(),
where other such cma reservations also gets called.
<stack trace>
==============
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10010
flags: 0x13ffff800000000(node=1|zone=0|lastcpupid=0x7ffff) CMA
raw: 013ffff800000000 5deadbeef0000100 5deadbeef0000122 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: VM_BUG_ON_PAGE(pfn & ((1 << order) - 1))
------------[ cut here ]------------
kernel BUG at mm/page_alloc.c:778!
Call Trace:
__free_one_page+0x57c/0x7b0 (unreliable)
free_pcppages_bulk+0x1a8/0x2c8
free_unref_page_commit+0x3d4/0x4e4
free_unref_page+0x458/0x6d0
init_cma_reserved_pageblock+0x114/0x198
cma_init_reserved_areas+0x270/0x3e0
do_one_initcall+0x80/0x2f8
kernel_init_freeable+0x33c/0x530
kernel_init+0x34/0x26c
ret_from_kernel_user_thread+0x14/0x1c
In the Linux kernel, the following vulnerability has been resolved:
powerpc/mm/fault: Fix kfence page fault reporting
copy_from_kernel_nofault() can be called when doing read of /proc/kcore.
/proc/kcore can have some unmapped kfence objects which when read via
copy_from_kernel_nofault() can cause page faults. Since *_nofault()
functions define their own fixup table for handling fault, use that
instead of asking kfence to handle such faults.
Hence we search the exception tables for the nip which generated the
fault. If there is an entry then we let the fixup table handler handle the
page fault by returning an error from within ___do_page_fault().
This can be easily triggered if someone tries to do dd from /proc/kcore.
eg. dd if=/proc/kcore of=/dev/null bs=1M
Some example false negatives:
===============================
BUG: KFENCE: invalid read in copy_from_kernel_nofault+0x9c/0x1a0
Invalid read at 0xc0000000fdff0000:
copy_from_kernel_nofault+0x9c/0x1a0
0xc00000000665f950
read_kcore_iter+0x57c/0xa04
proc_reg_read_iter+0xe4/0x16c
vfs_read+0x320/0x3ec
ksys_read+0x90/0x154
system_call_exception+0x120/0x310
system_call_vectored_common+0x15c/0x2ec
BUG: KFENCE: use-after-free read in copy_from_kernel_nofault+0x9c/0x1a0
Use-after-free read at 0xc0000000fe050000 (in kfence-#2):
copy_from_kernel_nofault+0x9c/0x1a0
0xc00000000665f950
read_kcore_iter+0x57c/0xa04
proc_reg_read_iter+0xe4/0x16c
vfs_read+0x320/0x3ec
ksys_read+0x90/0x154
system_call_exception+0x120/0x310
system_call_vectored_common+0x15c/0x2ec
In the Linux kernel, the following vulnerability has been resolved:
blk-cgroup: Fix UAF in blkcg_unpin_online()
blkcg_unpin_online() walks up the blkcg hierarchy putting the online pin. To
walk up, it uses blkcg_parent(blkcg) but it was calling that after
blkcg_destroy_blkgs(blkcg) which could free the blkcg, leading to the
following UAF:
==================================================================
BUG: KASAN: slab-use-after-free in blkcg_unpin_online+0x15a/0x270
Read of size 8 at addr ffff8881057678c0 by task kworker/9:1/117
CPU: 9 UID: 0 PID: 117 Comm: kworker/9:1 Not tainted 6.13.0-rc1-work-00182-gb8f52214c61a-dirty #48
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS unknown 02/02/2022
Workqueue: cgwb_release cgwb_release_workfn
Call Trace:
<TASK>
dump_stack_lvl+0x27/0x80
print_report+0x151/0x710
kasan_report+0xc0/0x100
blkcg_unpin_online+0x15a/0x270
cgwb_release_workfn+0x194/0x480
process_scheduled_works+0x71b/0xe20
worker_thread+0x82a/0xbd0
kthread+0x242/0x2c0
ret_from_fork+0x33/0x70
ret_from_fork_asm+0x1a/0x30
</TASK>
...
Freed by task 1944:
kasan_save_track+0x2b/0x70
kasan_save_free_info+0x3c/0x50
__kasan_slab_free+0x33/0x50
kfree+0x10c/0x330
css_free_rwork_fn+0xe6/0xb30
process_scheduled_works+0x71b/0xe20
worker_thread+0x82a/0xbd0
kthread+0x242/0x2c0
ret_from_fork+0x33/0x70
ret_from_fork_asm+0x1a/0x30
Note that the UAF is not easy to trigger as the free path is indirected
behind a couple RCU grace periods and a work item execution. I could only
trigger it with artifical msleep() injected in blkcg_unpin_online().
Fix it by reading the parent pointer before destroying the blkcg's blkg's.
In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix UAF via mismatching bpf_prog/attachment RCU flavors
Uprobes always use bpf_prog_run_array_uprobe() under tasks-trace-RCU
protection. But it is possible to attach a non-sleepable BPF program to a
uprobe, and non-sleepable BPF programs are freed via normal RCU (see
__bpf_prog_put_noref()). This leads to UAF of the bpf_prog because a normal
RCU grace period does not imply a tasks-trace-RCU grace period.
Fix it by explicitly waiting for a tasks-trace-RCU grace period after
removing the attachment of a bpf_prog to a perf_event.
In the Linux kernel, the following vulnerability has been resolved:
acpi: nfit: vmalloc-out-of-bounds Read in acpi_nfit_ctl
Fix an issue detected by syzbot with KASAN:
BUG: KASAN: vmalloc-out-of-bounds in cmd_to_func drivers/acpi/nfit/
core.c:416 [inline]
BUG: KASAN: vmalloc-out-of-bounds in acpi_nfit_ctl+0x20e8/0x24a0
drivers/acpi/nfit/core.c:459
The issue occurs in cmd_to_func when the call_pkg->nd_reserved2
array is accessed without verifying that call_pkg points to a buffer
that is appropriately sized as a struct nd_cmd_pkg. This can lead
to out-of-bounds access and undefined behavior if the buffer does not
have sufficient space.
To address this, a check was added in acpi_nfit_ctl() to ensure that
buf is not NULL and that buf_len is less than sizeof(*call_pkg)
before accessing it. This ensures safe access to the members of
call_pkg, including the nd_reserved2 array.
In the Linux kernel, the following vulnerability has been resolved:
bpf, sockmap: Fix race between element replace and close()
Element replace (with a socket different from the one stored) may race
with socket's close() link popping & unlinking. __sock_map_delete()
unconditionally unrefs the (wrong) element:
// set map[0] = s0
map_update_elem(map, 0, s0)
// drop fd of s0
close(s0)
sock_map_close()
lock_sock(sk) (s0!)
sock_map_remove_links(sk)
link = sk_psock_link_pop()
sock_map_unlink(sk, link)
sock_map_delete_from_link
// replace map[0] with s1
map_update_elem(map, 0, s1)
sock_map_update_elem
(s1!) lock_sock(sk)
sock_map_update_common
psock = sk_psock(sk)
spin_lock(&stab->lock)
osk = stab->sks[idx]
sock_map_add_link(..., &stab->sks[idx])
sock_map_unref(osk, &stab->sks[idx])
psock = sk_psock(osk)
sk_psock_put(sk, psock)
if (refcount_dec_and_test(&psock))
sk_psock_drop(sk, psock)
spin_unlock(&stab->lock)
unlock_sock(sk)
__sock_map_delete
spin_lock(&stab->lock)
sk = *psk // s1 replaced s0; sk == s1
if (!sk_test || sk_test == sk) // sk_test (s0) != sk (s1); no branch
sk = xchg(psk, NULL)
if (sk)
sock_map_unref(sk, psk) // unref s1; sks[idx] will dangle
psock = sk_psock(sk)
sk_psock_put(sk, psock)
if (refcount_dec_and_test())
sk_psock_drop(sk, psock)
spin_unlock(&stab->lock)
release_sock(sk)
Then close(map) enqueues bpf_map_free_deferred, which finally calls
sock_map_free(). This results in some refcount_t warnings along with
a KASAN splat [1].
Fix __sock_map_delete(), do not allow sock_map_unref() on elements that
may have been replaced.
[1]:
BUG: KASAN: slab-use-after-free in sock_map_free+0x10e/0x330
Write of size 4 at addr ffff88811f5b9100 by task kworker/u64:12/1063
CPU: 14 UID: 0 PID: 1063 Comm: kworker/u64:12 Not tainted 6.12.0+ #125
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014
Workqueue: events_unbound bpf_map_free_deferred
Call Trace:
<TASK>
dump_stack_lvl+0x68/0x90
print_report+0x174/0x4f6
kasan_report+0xb9/0x190
kasan_check_range+0x10f/0x1e0
sock_map_free+0x10e/0x330
bpf_map_free_deferred+0x173/0x320
process_one_work+0x846/0x1420
worker_thread+0x5b3/0xf80
kthread+0x29e/0x360
ret_from_fork+0x2d/0x70
ret_from_fork_asm+0x1a/0x30
</TASK>
Allocated by task 1202:
kasan_save_stack+0x1e/0x40
kasan_save_track+0x10/0x30
__kasan_slab_alloc+0x85/0x90
kmem_cache_alloc_noprof+0x131/0x450
sk_prot_alloc+0x5b/0x220
sk_alloc+0x2c/0x870
unix_create1+0x88/0x8a0
unix_create+0xc5/0x180
__sock_create+0x241/0x650
__sys_socketpair+0x1ce/0x420
__x64_sys_socketpair+0x92/0x100
do_syscall_64+0x93/0x180
entry_SYSCALL_64_after_hwframe+0x76/0x7e
Freed by task 46:
kasan_save_stack+0x1e/0x40
kasan_save_track+0x10/0x30
kasan_save_free_info+0x37/0x60
__kasan_slab_free+0x4b/0x70
kmem_cache_free+0x1a1/0x590
__sk_destruct+0x388/0x5a0
sk_psock_destroy+0x73e/0xa50
process_one_work+0x846/0x1420
worker_thread+0x5b3/0xf80
kthread+0x29e/0x360
ret_from_fork+0x2d/0x70
ret_from_fork_asm+0x1a/0x30
The bu
---truncated---
In the Linux kernel, the following vulnerability has been resolved:
usb: gadget: u_serial: Fix the issue that gs_start_io crashed due to accessing null pointer
Considering that in some extreme cases,
when u_serial driver is accessed by multiple threads,
Thread A is executing the open operation and calling the gs_open,
Thread B is executing the disconnect operation and calling the
gserial_disconnect function,The port->port_usb pointer will be set to NULL.
E.g.
Thread A Thread B
gs_open() gadget_unbind_driver()
gs_start_io() composite_disconnect()
gs_start_rx() gserial_disconnect()
... ...
spin_unlock(&port->port_lock)
status = usb_ep_queue() spin_lock(&port->port_lock)
spin_lock(&port->port_lock) port->port_usb = NULL
gs_free_requests(port->port_usb->in) spin_unlock(&port->port_lock)
Crash
This causes thread A to access a null pointer (port->port_usb is null)
when calling the gs_free_requests function, causing a crash.
If port_usb is NULL, the release request will be skipped as it
will be done by gserial_disconnect.
So add a null pointer check to gs_start_io before attempting
to access the value of the pointer port->port_usb.
Call trace:
gs_start_io+0x164/0x25c
gs_open+0x108/0x13c
tty_open+0x314/0x638
chrdev_open+0x1b8/0x258
do_dentry_open+0x2c4/0x700
vfs_open+0x2c/0x3c
path_openat+0xa64/0xc60
do_filp_open+0xb8/0x164
do_sys_openat2+0x84/0xf0
__arm64_sys_openat+0x70/0x9c
invoke_syscall+0x58/0x114
el0_svc_common+0x80/0xe0
do_el0_svc+0x1c/0x28
el0_svc+0x38/0x68