In the Linux kernel, the following vulnerability has been resolved:
mm/migrate: fix shmem xarray update during migration
A shmem folio can be either in page cache or in swap cache, but not at the
same time. Namely, once it is in swap cache, folio->mapping should be
NULL, and the folio is no longer in a shmem mapping.
In __folio_migrate_mapping(), to determine the number of xarray entries to
update, folio_test_swapbacked() is used, but that conflates shmem in page
cache case and shmem in swap cache case. It leads to xarray multi-index
entry corruption, since it turns a sibling entry to a normal entry during
xas_store() (see [1] for a userspace reproduction). Fix it by only using
folio_test_swapcache() to determine whether xarray is storing swap cache
entries or not to choose the right number of xarray entries to update.
[1] https://lore.kernel.org/linux-mm/Z8idPCkaJW1IChjT@casper.infradead.org/
Note:
In __split_huge_page(), folio_test_anon() && folio_test_swapcache() is
used to get swap_cache address space, but that ignores the shmem folio in
swap cache case. It could lead to NULL pointer dereferencing when a
in-swap-cache shmem folio is split at __xa_store(), since
!folio_test_anon() is true and folio->mapping is NULL. But fortunately,
its caller split_huge_page_to_list_to_order() bails out early with EBUSY
when folio->mapping is NULL. So no need to take care of it here.
In the Linux kernel, the following vulnerability has been resolved:
soc: qcom: pdr: Fix the potential deadlock
When some client process A call pdr_add_lookup() to add the look up for
the service and does schedule locator work, later a process B got a new
server packet indicating locator is up and call pdr_locator_new_server()
which eventually sets pdr->locator_init_complete to true which process A
sees and takes list lock and queries domain list but it will timeout due
to deadlock as the response will queued to the same qmi->wq and it is
ordered workqueue and process B is not able to complete new server
request work due to deadlock on list lock.
Fix it by removing the unnecessary list iteration as the list iteration
is already being done inside locator work, so avoid it here and just
call schedule_work() here.
Process A Process B
process_scheduled_works()
pdr_add_lookup() qmi_data_ready_work()
process_scheduled_works() pdr_locator_new_server()
pdr->locator_init_complete=true;
pdr_locator_work()
mutex_lock(&pdr->list_lock);
pdr_locate_service() mutex_lock(&pdr->list_lock);
pdr_get_domain_list()
pr_err("PDR: %s get domain list
txn wait failed: %d\n",
req->service_name,
ret);
Timeout error log due to deadlock:
"
PDR: tms/servreg get domain list txn wait failed: -110
PDR: service lookup for msm/adsp/sensor_pd:tms/servreg failed: -110
"
Thanks to Bjorn and Johan for letting me know that this commit also fixes
an audio regression when using the in-kernel pd-mapper as that makes it
easier to hit this race. [1]
In the Linux kernel, the following vulnerability has been resolved:
regulator: check that dummy regulator has been probed before using it
Due to asynchronous driver probing there is a chance that the dummy
regulator hasn't already been probed when first accessing it.
In the Linux kernel, the following vulnerability has been resolved:
RDMA/hns: Fix soft lockup during bt pages loop
Driver runs a for-loop when allocating bt pages and mapping them with
buffer pages. When a large buffer (e.g. MR over 100GB) is being allocated,
it may require a considerable loop count. This will lead to soft lockup:
watchdog: BUG: soft lockup - CPU#27 stuck for 22s!
...
Call trace:
hem_list_alloc_mid_bt+0x124/0x394 [hns_roce_hw_v2]
hns_roce_hem_list_request+0xf8/0x160 [hns_roce_hw_v2]
hns_roce_mtr_create+0x2e4/0x360 [hns_roce_hw_v2]
alloc_mr_pbl+0xd4/0x17c [hns_roce_hw_v2]
hns_roce_reg_user_mr+0xf8/0x190 [hns_roce_hw_v2]
ib_uverbs_reg_mr+0x118/0x290
watchdog: BUG: soft lockup - CPU#35 stuck for 23s!
...
Call trace:
hns_roce_hem_list_find_mtt+0x7c/0xb0 [hns_roce_hw_v2]
mtr_map_bufs+0xc4/0x204 [hns_roce_hw_v2]
hns_roce_mtr_create+0x31c/0x3c4 [hns_roce_hw_v2]
alloc_mr_pbl+0xb0/0x160 [hns_roce_hw_v2]
hns_roce_reg_user_mr+0x108/0x1c0 [hns_roce_hw_v2]
ib_uverbs_reg_mr+0x120/0x2bc
Add a cond_resched() to fix soft lockup during these loops. In order not
to affect the allocation performance of normal-size buffer, set the loop
count of a 100GB MR as the threshold to call cond_resched().
In the Linux kernel, the following vulnerability has been resolved:
ipv6: Fix memleak of nhc_pcpu_rth_output in fib_check_nh_v6_gw().
fib_check_nh_v6_gw() expects that fib6_nh_init() cleans up everything
when it fails.
Commit 7dd73168e273 ("ipv6: Always allocate pcpu memory in a fib6_nh")
moved fib_nh_common_init() before alloc_percpu_gfp() within fib6_nh_init()
but forgot to add cleanup for fib6_nh->nh_common.nhc_pcpu_rth_output in
case it fails to allocate fib6_nh->rt6i_pcpu, resulting in memleak.
Let's call fib_nh_common_release() and clear nhc_pcpu_rth_output in the
error path.
Note that we can remove the fib6_nh_release() call in nh_create_ipv6()
later in net-next.git.
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: Fix error code in chan_alloc_skb_cb()
The chan_alloc_skb_cb() function is supposed to return error pointers on
error. Returning NULL will lead to a NULL dereference.
In the Linux kernel, the following vulnerability has been resolved:
drm/radeon: fix uninitialized size issue in radeon_vce_cs_parse()
On the off chance that command stream passed from userspace via
ioctl() call to radeon_vce_cs_parse() is weirdly crafted and
first command to execute is to encode (case 0x03000001), the function
in question will attempt to call radeon_vce_cs_reloc() with size
argument that has not been properly initialized. Specifically, 'size'
will point to 'tmp' variable before the latter had a chance to be
assigned any value.
Play it safe and init 'tmp' with 0, thus ensuring that
radeon_vce_cs_reloc() will catch an early error in cases like these.
Found by Linux Verification Center (linuxtesting.org) with static
analysis tool SVACE.
(cherry picked from commit 2d52de55f9ee7aaee0e09ac443f77855989c6b68)
In the Linux kernel, the following vulnerability has been resolved:
xsk: fix an integer overflow in xp_create_and_assign_umem()
Since the i and pool->chunk_size variables are of type 'u32',
their product can wrap around and then be cast to 'u64'.
This can lead to two different XDP buffers pointing to the same
memory area.
Found by InfoTeCS on behalf of Linux Verification Center
(linuxtesting.org) with SVACE.
In the Linux kernel, the following vulnerability has been resolved:
proc: fix UAF in proc_get_inode()
Fix race between rmmod and /proc/XXX's inode instantiation.
The bug is that pde->proc_ops don't belong to /proc, it belongs to a
module, therefore dereferencing it after /proc entry has been registered
is a bug unless use_pde/unuse_pde() pair has been used.
use_pde/unuse_pde can be avoided (2 atomic ops!) because pde->proc_ops
never changes so information necessary for inode instantiation can be
saved _before_ proc_register() in PDE itself and used later, avoiding
pde->proc_ops->... dereference.
rmmod lookup
sys_delete_module
proc_lookup_de
pde_get(de);
proc_get_inode(dir->i_sb, de);
mod->exit()
proc_remove
remove_proc_subtree
proc_entry_rundown(de);
free_module(mod);
if (S_ISREG(inode->i_mode))
if (de->proc_ops->proc_read_iter)
--> As module is already freed, will trigger UAF
BUG: unable to handle page fault for address: fffffbfff80a702b
PGD 817fc4067 P4D 817fc4067 PUD 817fc0067 PMD 102ef4067 PTE 0
Oops: Oops: 0000 [#1] PREEMPT SMP KASAN PTI
CPU: 26 UID: 0 PID: 2667 Comm: ls Tainted: G
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)
RIP: 0010:proc_get_inode+0x302/0x6e0
RSP: 0018:ffff88811c837998 EFLAGS: 00010a06
RAX: dffffc0000000000 RBX: ffffffffc0538140 RCX: 0000000000000007
RDX: 1ffffffff80a702b RSI: 0000000000000001 RDI: ffffffffc0538158
RBP: ffff8881299a6000 R08: 0000000067bbe1e5 R09: 1ffff11023906f20
R10: ffffffffb560ca07 R11: ffffffffb2b43a58 R12: ffff888105bb78f0
R13: ffff888100518048 R14: ffff8881299a6004 R15: 0000000000000001
FS: 00007f95b9686840(0000) GS:ffff8883af100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffbfff80a702b CR3: 0000000117dd2000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
proc_lookup_de+0x11f/0x2e0
__lookup_slow+0x188/0x350
walk_component+0x2ab/0x4f0
path_lookupat+0x120/0x660
filename_lookup+0x1ce/0x560
vfs_statx+0xac/0x150
__do_sys_newstat+0x96/0x110
do_syscall_64+0x5f/0x170
entry_SYSCALL_64_after_hwframe+0x76/0x7e
[adobriyan@gmail.com: don't do 2 atomic ops on the common path]