| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
riscv: fix race when vmap stack overflow
Currently, when detecting vmap stack overflow, riscv firstly switches
to the so called shadow stack, then use this shadow stack to call the
get_overflow_stack() to get the overflow stack. However, there's
a race here if two or more harts use the same shadow stack at the same
time.
To solve this race, we introduce spin_shadow_stack atomic var, which
will be swap between its own address and 0 in atomic way, when the
var is set, it means the shadow_stack is being used; when the var
is cleared, it means the shadow_stack isn't being used.
[Palmer: Add AQ to the swap, and also some comments.] |
| In the Linux kernel, the following vulnerability has been resolved:
char: tpm: Protect tpm_pm_suspend with locks
Currently tpm transactions are executed unconditionally in
tpm_pm_suspend() function, which may lead to races with other tpm
accessors in the system.
Specifically, the hw_random tpm driver makes use of tpm_get_random(),
and this function is called in a loop from a kthread, which means it's
not frozen alongside userspace, and so can race with the work done
during system suspend:
tpm tpm0: tpm_transmit: tpm_recv: error -52
tpm tpm0: invalid TPM_STS.x 0xff, dumping stack for forensics
CPU: 0 PID: 1 Comm: init Not tainted 6.1.0-rc5+ #135
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.0-20220807_005459-localhost 04/01/2014
Call Trace:
tpm_tis_status.cold+0x19/0x20
tpm_transmit+0x13b/0x390
tpm_transmit_cmd+0x20/0x80
tpm1_pm_suspend+0xa6/0x110
tpm_pm_suspend+0x53/0x80
__pnp_bus_suspend+0x35/0xe0
__device_suspend+0x10f/0x350
Fix this by calling tpm_try_get_ops(), which itself is a wrapper around
tpm_chip_start(), but takes the appropriate mutex.
[Jason: reworked commit message, added metadata] |
| In the Linux kernel, the following vulnerability has been resolved:
fscache: Fix oops due to race with cookie_lru and use_cookie
If a cookie expires from the LRU and the LRU_DISCARD flag is set, but
the state machine has not run yet, it's possible another thread can call
fscache_use_cookie and begin to use it.
When the cookie_worker finally runs, it will see the LRU_DISCARD flag
set, transition the cookie->state to LRU_DISCARDING, which will then
withdraw the cookie. Once the cookie is withdrawn the object is removed
the below oops will occur because the object associated with the cookie
is now NULL.
Fix the oops by clearing the LRU_DISCARD bit if another thread uses the
cookie before the cookie_worker runs.
BUG: kernel NULL pointer dereference, address: 0000000000000008
...
CPU: 31 PID: 44773 Comm: kworker/u130:1 Tainted: G E 6.0.0-5.dneg.x86_64 #1
Hardware name: Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022
Workqueue: events_unbound netfs_rreq_write_to_cache_work [netfs]
RIP: 0010:cachefiles_prepare_write+0x28/0x90 [cachefiles]
...
Call Trace:
netfs_rreq_write_to_cache_work+0x11c/0x320 [netfs]
process_one_work+0x217/0x3e0
worker_thread+0x4a/0x3b0
kthread+0xd6/0x100 |
| In the Linux kernel, the following vulnerability has been resolved:
configfs: fix a race in configfs_{,un}register_subsystem()
When configfs_register_subsystem() or configfs_unregister_subsystem()
is executing link_group() or unlink_group(),
it is possible that two processes add or delete list concurrently.
Some unfortunate interleavings of them can cause kernel panic.
One of cases is:
A --> B --> C --> D
A <-- B <-- C <-- D
delete list_head *B | delete list_head *C
--------------------------------|-----------------------------------
configfs_unregister_subsystem | configfs_unregister_subsystem
unlink_group | unlink_group
unlink_obj | unlink_obj
list_del_init | list_del_init
__list_del_entry | __list_del_entry
__list_del | __list_del
// next == C |
next->prev = prev |
| next->prev = prev
prev->next = next |
| // prev == B
| prev->next = next
Fix this by adding mutex when calling link_group() or unlink_group(),
but parent configfs_subsystem is NULL when config_item is root.
So I create a mutex configfs_subsystem_mutex. |
| In the Linux kernel, the following vulnerability has been resolved:
btrfs: fix relocation crash due to premature return from btrfs_commit_transaction()
We are seeing crashes similar to the following trace:
[38.969182] WARNING: CPU: 20 PID: 2105 at fs/btrfs/relocation.c:4070 btrfs_relocate_block_group+0x2dc/0x340 [btrfs]
[38.973556] CPU: 20 PID: 2105 Comm: btrfs Not tainted 5.17.0-rc4 #54
[38.974580] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
[38.976539] RIP: 0010:btrfs_relocate_block_group+0x2dc/0x340 [btrfs]
[38.980336] RSP: 0000:ffffb0dd42e03c20 EFLAGS: 00010206
[38.981218] RAX: ffff96cfc4ede800 RBX: ffff96cfc3ce0000 RCX: 000000000002ca14
[38.982560] RDX: 0000000000000000 RSI: 4cfd109a0bcb5d7f RDI: ffff96cfc3ce0360
[38.983619] RBP: ffff96cfc309c000 R08: 0000000000000000 R09: 0000000000000000
[38.984678] R10: ffff96cec0000001 R11: ffffe84c80000000 R12: ffff96cfc4ede800
[38.985735] R13: 0000000000000000 R14: 0000000000000000 R15: ffff96cfc3ce0360
[38.987146] FS: 00007f11c15218c0(0000) GS:ffff96d6dfb00000(0000) knlGS:0000000000000000
[38.988662] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[38.989398] CR2: 00007ffc922c8e60 CR3: 00000001147a6001 CR4: 0000000000370ee0
[38.990279] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[38.991219] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[38.992528] Call Trace:
[38.992854] <TASK>
[38.993148] btrfs_relocate_chunk+0x27/0xe0 [btrfs]
[38.993941] btrfs_balance+0x78e/0xea0 [btrfs]
[38.994801] ? vsnprintf+0x33c/0x520
[38.995368] ? __kmalloc_track_caller+0x351/0x440
[38.996198] btrfs_ioctl_balance+0x2b9/0x3a0 [btrfs]
[38.997084] btrfs_ioctl+0x11b0/0x2da0 [btrfs]
[38.997867] ? mod_objcg_state+0xee/0x340
[38.998552] ? seq_release+0x24/0x30
[38.999184] ? proc_nr_files+0x30/0x30
[38.999654] ? call_rcu+0xc8/0x2f0
[39.000228] ? __x64_sys_ioctl+0x84/0xc0
[39.000872] ? btrfs_ioctl_get_supported_features+0x30/0x30 [btrfs]
[39.001973] __x64_sys_ioctl+0x84/0xc0
[39.002566] do_syscall_64+0x3a/0x80
[39.003011] entry_SYSCALL_64_after_hwframe+0x44/0xae
[39.003735] RIP: 0033:0x7f11c166959b
[39.007324] RSP: 002b:00007fff2543e998 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
[39.008521] RAX: ffffffffffffffda RBX: 00007f11c1521698 RCX: 00007f11c166959b
[39.009833] RDX: 00007fff2543ea40 RSI: 00000000c4009420 RDI: 0000000000000003
[39.011270] RBP: 0000000000000003 R08: 0000000000000013 R09: 00007f11c16f94e0
[39.012581] R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff25440df3
[39.014046] R13: 0000000000000000 R14: 00007fff2543ea40 R15: 0000000000000001
[39.015040] </TASK>
[39.015418] ---[ end trace 0000000000000000 ]---
[43.131559] ------------[ cut here ]------------
[43.132234] kernel BUG at fs/btrfs/extent-tree.c:2717!
[43.133031] invalid opcode: 0000 [#1] PREEMPT SMP PTI
[43.133702] CPU: 1 PID: 1839 Comm: btrfs Tainted: G W 5.17.0-rc4 #54
[43.134863] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
[43.136426] RIP: 0010:unpin_extent_range+0x37a/0x4f0 [btrfs]
[43.139913] RSP: 0000:ffffb0dd4216bc70 EFLAGS: 00010246
[43.140629] RAX: 0000000000000000 RBX: ffff96cfc34490f8 RCX: 0000000000000001
[43.141604] RDX: 0000000080000001 RSI: 0000000051d00000 RDI: 00000000ffffffff
[43.142645] RBP: 0000000000000000 R08: 0000000000000000 R09: ffff96cfd07dca50
[43.143669] R10: ffff96cfc46e8a00 R11: fffffffffffec000 R12: 0000000041d00000
[43.144657] R13: ffff96cfc3ce0000 R14: ffffb0dd4216bd08 R15: 0000000000000000
[43.145686] FS: 00007f7657dd68c0(0000) GS:ffff96d6df640000(0000) knlGS:0000000000000000
[43.146808] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[43.147584] CR2: 00007f7fe81bf5b0 CR3: 00000001093ee004 CR4: 0000000000370ee0
[43.148589] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[43.149581] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 00000000000
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
btrfs: do not start relocation until in progress drops are done
We hit a bug with a recovering relocation on mount for one of our file
systems in production. I reproduced this locally by injecting errors
into snapshot delete with balance running at the same time. This
presented as an error while looking up an extent item
WARNING: CPU: 5 PID: 1501 at fs/btrfs/extent-tree.c:866 lookup_inline_extent_backref+0x647/0x680
CPU: 5 PID: 1501 Comm: btrfs-balance Not tainted 5.16.0-rc8+ #8
RIP: 0010:lookup_inline_extent_backref+0x647/0x680
RSP: 0018:ffffae0a023ab960 EFLAGS: 00010202
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 000000000000000c RDI: 0000000000000000
RBP: ffff943fd2a39b60 R08: 0000000000000000 R09: 0000000000000001
R10: 0001434088152de0 R11: 0000000000000000 R12: 0000000001d05000
R13: ffff943fd2a39b60 R14: ffff943fdb96f2a0 R15: ffff9442fc923000
FS: 0000000000000000(0000) GS:ffff944e9eb40000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1157b1fca8 CR3: 000000010f092000 CR4: 0000000000350ee0
Call Trace:
<TASK>
insert_inline_extent_backref+0x46/0xd0
__btrfs_inc_extent_ref.isra.0+0x5f/0x200
? btrfs_merge_delayed_refs+0x164/0x190
__btrfs_run_delayed_refs+0x561/0xfa0
? btrfs_search_slot+0x7b4/0xb30
? btrfs_update_root+0x1a9/0x2c0
btrfs_run_delayed_refs+0x73/0x1f0
? btrfs_update_root+0x1a9/0x2c0
btrfs_commit_transaction+0x50/0xa50
? btrfs_update_reloc_root+0x122/0x220
prepare_to_merge+0x29f/0x320
relocate_block_group+0x2b8/0x550
btrfs_relocate_block_group+0x1a6/0x350
btrfs_relocate_chunk+0x27/0xe0
btrfs_balance+0x777/0xe60
balance_kthread+0x35/0x50
? btrfs_balance+0xe60/0xe60
kthread+0x16b/0x190
? set_kthread_struct+0x40/0x40
ret_from_fork+0x22/0x30
</TASK>
Normally snapshot deletion and relocation are excluded from running at
the same time by the fs_info->cleaner_mutex. However if we had a
pending balance waiting to get the ->cleaner_mutex, and a snapshot
deletion was running, and then the box crashed, we would come up in a
state where we have a half deleted snapshot.
Again, in the normal case the snapshot deletion needs to complete before
relocation can start, but in this case relocation could very well start
before the snapshot deletion completes, as we simply add the root to the
dead roots list and wait for the next time the cleaner runs to clean up
the snapshot.
Fix this by setting a bit on the fs_info if we have any DEAD_ROOT's that
had a pending drop_progress key. If they do then we know we were in the
middle of the drop operation and set a flag on the fs_info. Then
balance can wait until this flag is cleared to start up again.
If there are DEAD_ROOT's that don't have a drop_progress set then we're
safe to start balance right away as we'll be properly protected by the
cleaner_mutex. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/msm/dp: do not complete dp_aux_cmd_fifo_tx() if irq is not for aux transfer
There are 3 possible interrupt sources are handled by DP controller,
HPDstatus, Controller state changes and Aux read/write transaction.
At every irq, DP controller have to check isr status of every interrupt
sources and service the interrupt if its isr status bits shows interrupts
are pending. There is potential race condition may happen at current aux
isr handler implementation since it is always complete dp_aux_cmd_fifo_tx()
even irq is not for aux read or write transaction. This may cause aux read
transaction return premature if host aux data read is in the middle of
waiting for sink to complete transferring data to host while irq happen.
This will cause host's receiving buffer contains unexpected data. This
patch fixes this problem by checking aux isr and return immediately at
aux isr handler if there are no any isr status bits set.
Current there is a bug report regrading eDP edid corruption happen during
system booting up. After lengthy debugging to found that VIDEO_READY
interrupt was continuously firing during system booting up which cause
dp_aux_isr() to complete dp_aux_cmd_fifo_tx() prematurely to retrieve data
from aux hardware buffer which is not yet contains complete data transfer
from sink. This cause edid corruption.
Follows are the signature at kernel logs when problem happen,
EDID has corrupt header
panel-simple-dp-aux aux-aea0000.edp: Couldn't identify panel via EDID
Changes in v2:
-- do complete if (ret == IRQ_HANDLED) ay dp-aux_isr()
-- add more commit text
Changes in v3:
-- add Stephen suggested
-- dp_aux_isr() return IRQ_XXX back to caller
-- dp_ctrl_isr() return IRQ_XXX back to caller
Changes in v4:
-- split into two patches
Changes in v5:
-- delete empty line between tags
Changes in v6:
-- remove extra "that" and fixed line more than 75 char at commit text
Patchwork: https://patchwork.freedesktop.org/patch/516121/ |
| In the Linux kernel, the following vulnerability has been resolved:
drm/vmwgfx: Remove rcu locks from user resources
User resource lookups used rcu to avoid two extra atomics. Unfortunately
the rcu paths were buggy and it was easy to make the driver crash by
submitting command buffers from two different threads. Because the
lookups never show up in performance profiles replace them with a
regular spin lock which fixes the races in accesses to those shared
resources.
Fixes kernel oops'es in IGT's vmwgfx execution_buffer stress test and
seen crashes with apps using shared resources. |
| In the Linux kernel, the following vulnerability has been resolved:
tipc: fix kernel panic when enabling bearer
When enabling a bearer on a node, a kernel panic is observed:
[ 4.498085] RIP: 0010:tipc_mon_prep+0x4e/0x130 [tipc]
...
[ 4.520030] Call Trace:
[ 4.520689] <IRQ>
[ 4.521236] tipc_link_build_proto_msg+0x375/0x750 [tipc]
[ 4.522654] tipc_link_build_state_msg+0x48/0xc0 [tipc]
[ 4.524034] __tipc_node_link_up+0xd7/0x290 [tipc]
[ 4.525292] tipc_rcv+0x5da/0x730 [tipc]
[ 4.526346] ? __netif_receive_skb_core+0xb7/0xfc0
[ 4.527601] tipc_l2_rcv_msg+0x5e/0x90 [tipc]
[ 4.528737] __netif_receive_skb_list_core+0x20b/0x260
[ 4.530068] netif_receive_skb_list_internal+0x1bf/0x2e0
[ 4.531450] ? dev_gro_receive+0x4c2/0x680
[ 4.532512] napi_complete_done+0x6f/0x180
[ 4.533570] virtnet_poll+0x29c/0x42e [virtio_net]
...
The node in question is receiving activate messages in another
thread after changing bearer status to allow message sending/
receiving in current thread:
thread 1 | thread 2
-------- | --------
|
tipc_enable_bearer() |
test_and_set_bit_lock() |
tipc_bearer_xmit_skb() |
| tipc_l2_rcv_msg()
| tipc_rcv()
| __tipc_node_link_up()
| tipc_link_build_state_msg()
| tipc_link_build_proto_msg()
| tipc_mon_prep()
| {
| ...
| // null-pointer dereference
| u16 gen = mon->dom_gen;
| ...
| }
// Not being executed yet |
tipc_mon_create() |
{ |
... |
// allocate |
mon = kzalloc(); |
... |
} |
Monitoring pointer in thread 2 is dereferenced before monitoring data
is allocated in thread 1. This causes kernel panic.
This commit fixes it by allocating the monitoring data before enabling
the bearer to receive messages. |
| In the Linux kernel, the following vulnerability has been resolved:
tcp: TX zerocopy should not sense pfmemalloc status
We got a recent syzbot report [1] showing a possible misuse
of pfmemalloc page status in TCP zerocopy paths.
Indeed, for pages coming from user space or other layers,
using page_is_pfmemalloc() is moot, and possibly could give
false positives.
There has been attempts to make page_is_pfmemalloc() more robust,
but not using it in the first place in this context is probably better,
removing cpu cycles.
Note to stable teams :
You need to backport 84ce071e38a6 ("net: introduce
__skb_fill_page_desc_noacc") as a prereq.
Race is more probable after commit c07aea3ef4d4
("mm: add a signature in struct page") because page_is_pfmemalloc()
is now using low order bit from page->lru.next, which can change
more often than page->index.
Low order bit should never be set for lru.next (when used as an anchor
in LRU list), so KCSAN report is mostly a false positive.
Backporting to older kernel versions seems not necessary.
[1]
BUG: KCSAN: data-race in lru_add_fn / tcp_build_frag
write to 0xffffea0004a1d2c8 of 8 bytes by task 18600 on cpu 0:
__list_add include/linux/list.h:73 [inline]
list_add include/linux/list.h:88 [inline]
lruvec_add_folio include/linux/mm_inline.h:105 [inline]
lru_add_fn+0x440/0x520 mm/swap.c:228
folio_batch_move_lru+0x1e1/0x2a0 mm/swap.c:246
folio_batch_add_and_move mm/swap.c:263 [inline]
folio_add_lru+0xf1/0x140 mm/swap.c:490
filemap_add_folio+0xf8/0x150 mm/filemap.c:948
__filemap_get_folio+0x510/0x6d0 mm/filemap.c:1981
pagecache_get_page+0x26/0x190 mm/folio-compat.c:104
grab_cache_page_write_begin+0x2a/0x30 mm/folio-compat.c:116
ext4_da_write_begin+0x2dd/0x5f0 fs/ext4/inode.c:2988
generic_perform_write+0x1d4/0x3f0 mm/filemap.c:3738
ext4_buffered_write_iter+0x235/0x3e0 fs/ext4/file.c:270
ext4_file_write_iter+0x2e3/0x1210
call_write_iter include/linux/fs.h:2187 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x468/0x760 fs/read_write.c:578
ksys_write+0xe8/0x1a0 fs/read_write.c:631
__do_sys_write fs/read_write.c:643 [inline]
__se_sys_write fs/read_write.c:640 [inline]
__x64_sys_write+0x3e/0x50 fs/read_write.c:640
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
read to 0xffffea0004a1d2c8 of 8 bytes by task 18611 on cpu 1:
page_is_pfmemalloc include/linux/mm.h:1740 [inline]
__skb_fill_page_desc include/linux/skbuff.h:2422 [inline]
skb_fill_page_desc include/linux/skbuff.h:2443 [inline]
tcp_build_frag+0x613/0xb20 net/ipv4/tcp.c:1018
do_tcp_sendpages+0x3e8/0xaf0 net/ipv4/tcp.c:1075
tcp_sendpage_locked net/ipv4/tcp.c:1140 [inline]
tcp_sendpage+0x89/0xb0 net/ipv4/tcp.c:1150
inet_sendpage+0x7f/0xc0 net/ipv4/af_inet.c:833
kernel_sendpage+0x184/0x300 net/socket.c:3561
sock_sendpage+0x5a/0x70 net/socket.c:1054
pipe_to_sendpage+0x128/0x160 fs/splice.c:361
splice_from_pipe_feed fs/splice.c:415 [inline]
__splice_from_pipe+0x222/0x4d0 fs/splice.c:559
splice_from_pipe fs/splice.c:594 [inline]
generic_splice_sendpage+0x89/0xc0 fs/splice.c:743
do_splice_from fs/splice.c:764 [inline]
direct_splice_actor+0x80/0xa0 fs/splice.c:931
splice_direct_to_actor+0x305/0x620 fs/splice.c:886
do_splice_direct+0xfb/0x180 fs/splice.c:974
do_sendfile+0x3bf/0x910 fs/read_write.c:1249
__do_sys_sendfile64 fs/read_write.c:1317 [inline]
__se_sys_sendfile64 fs/read_write.c:1303 [inline]
__x64_sys_sendfile64+0x10c/0x150 fs/read_write.c:1303
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
value changed: 0x0000000000000000 -> 0xffffea0004a1d288
Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 18611 Comm: syz-executor.4 Not tainted 6.0.0-rc2-syzkaller-00248-ge022620b5d05-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: ufs: core: Fix racing issue between ufshcd_mcq_abort() and ISR
If command timeout happens and cq complete IRQ is raised at the same time,
ufshcd_mcq_abort clears lprb->cmd and a NULL pointer deref happens in the
ISR. Error log:
ufshcd_abort: Device abort task at tag 18
Unable to handle kernel NULL pointer dereference at virtual address
0000000000000108
pc : [0xffffffe27ef867ac] scsi_dma_unmap+0xc/0x44
lr : [0xffffffe27f1b898c] ufshcd_release_scsi_cmd+0x24/0x114 |
| In the Linux kernel, the following vulnerability has been resolved:
pmdomain: mediatek: fix race conditions with genpd
If the power domains are registered first with genpd and *after that*
the driver attempts to power them on in the probe sequence, then it is
possible that a race condition occurs if genpd tries to power them on
in the same time.
The same is valid for powering them off before unregistering them
from genpd.
Attempt to fix race conditions by first removing the domains from genpd
and *after that* powering down domains.
Also first power up the domains and *after that* register them
to genpd. |
| In the Linux kernel, the following vulnerability has been resolved:
KVM: s390: vsie: fix race during shadow creation
Right now it is possible to see gmap->private being zero in
kvm_s390_vsie_gmap_notifier resulting in a crash. This is due to the
fact that we add gmap->private == kvm after creation:
static int acquire_gmap_shadow(struct kvm_vcpu *vcpu,
struct vsie_page *vsie_page)
{
[...]
gmap = gmap_shadow(vcpu->arch.gmap, asce, edat);
if (IS_ERR(gmap))
return PTR_ERR(gmap);
gmap->private = vcpu->kvm;
Let children inherit the private field of the parent. |
| In the Linux kernel, the following vulnerability has been resolved:
binder: fix race between mmput() and do_exit()
Task A calls binder_update_page_range() to allocate and insert pages on
a remote address space from Task B. For this, Task A pins the remote mm
via mmget_not_zero() first. This can race with Task B do_exit() and the
final mmput() refcount decrement will come from Task A.
Task A | Task B
------------------+------------------
mmget_not_zero() |
| do_exit()
| exit_mm()
| mmput()
mmput() |
exit_mmap() |
remove_vma() |
fput() |
In this case, the work of ____fput() from Task B is queued up in Task A
as TWA_RESUME. So in theory, Task A returns to userspace and the cleanup
work gets executed. However, Task A instead sleep, waiting for a reply
from Task B that never comes (it's dead).
This means the binder_deferred_release() is blocked until an unrelated
binder event forces Task A to go back to userspace. All the associated
death notifications will also be delayed until then.
In order to fix this use mmput_async() that will schedule the work in
the corresponding mm->async_put_work WQ instead of Task A. |
| In the Linux kernel, the following vulnerability has been resolved:
firmware: arm_scmi: Check mailbox/SMT channel for consistency
On reception of a completion interrupt the shared memory area is accessed
to retrieve the message header at first and then, if the message sequence
number identifies a transaction which is still pending, the related
payload is fetched too.
When an SCMI command times out the channel ownership remains with the
platform until eventually a late reply is received and, as a consequence,
any further transmission attempt remains pending, waiting for the channel
to be relinquished by the platform.
Once that late reply is received the channel ownership is given back
to the agent and any pending request is then allowed to proceed and
overwrite the SMT area of the just delivered late reply; then the wait
for the reply to the new request starts.
It has been observed that the spurious IRQ related to the late reply can
be wrongly associated with the freshly enqueued request: when that happens
the SCMI stack in-flight lookup procedure is fooled by the fact that the
message header now present in the SMT area is related to the new pending
transaction, even though the real reply has still to arrive.
This race-condition on the A2P channel can be detected by looking at the
channel status bits: a genuine reply from the platform will have set the
channel free bit before triggering the completion IRQ.
Add a consistency check to validate such condition in the A2P ISR. |
| In the Linux kernel, the following vulnerability has been resolved:
media: rkisp1: Fix IRQ disable race issue
In rkisp1_isp_stop() and rkisp1_csi_disable() the driver masks the
interrupts and then apparently assumes that the interrupt handler won't
be running, and proceeds in the stop procedure. This is not the case, as
the interrupt handler can already be running, which would lead to the
ISP being disabled while the interrupt handler handling a captured
frame.
This brings up two issues: 1) the ISP could be powered off while the
interrupt handler is still running and accessing registers, leading to
board lockup, and 2) the interrupt handler code and the code that
disables the streaming might do things that conflict.
It is not clear to me if 2) causes a real issue, but 1) can be seen with
a suitable delay (or printk in my case) in the interrupt handler,
leading to board lockup. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/msm/dpu: Add mutex lock in control vblank irq
Add a mutex lock to control vblank irq to synchronize vblank
enable/disable operations happening from different threads to prevent
race conditions while registering/unregistering the vblank irq callback.
v4: -Removed vblank_ctl_lock from dpu_encoder_virt, so it is only a
parameter of dpu_encoder_phys.
-Switch from atomic refcnt to a simple int counter as mutex has
now been added
v3: Mistakenly did not change wording in last version. It is done now.
v2: Slightly changed wording of commit message
Patchwork: https://patchwork.freedesktop.org/patch/571854/ |
| In the Linux kernel, the following vulnerability has been resolved:
net: bridge: use DEV_STATS_INC()
syzbot/KCSAN reported data-races in br_handle_frame_finish() [1]
This function can run from multiple cpus without mutual exclusion.
Adopt SMP safe DEV_STATS_INC() to update dev->stats fields.
Handles updates to dev->stats.tx_dropped while we are at it.
[1]
BUG: KCSAN: data-race in br_handle_frame_finish / br_handle_frame_finish
read-write to 0xffff8881374b2178 of 8 bytes by interrupt on cpu 1:
br_handle_frame_finish+0xd4f/0xef0 net/bridge/br_input.c:189
br_nf_hook_thresh+0x1ed/0x220
br_nf_pre_routing_finish_ipv6+0x50f/0x540
NF_HOOK include/linux/netfilter.h:304 [inline]
br_nf_pre_routing_ipv6+0x1e3/0x2a0 net/bridge/br_netfilter_ipv6.c:178
br_nf_pre_routing+0x526/0xba0 net/bridge/br_netfilter_hooks.c:508
nf_hook_entry_hookfn include/linux/netfilter.h:144 [inline]
nf_hook_bridge_pre net/bridge/br_input.c:272 [inline]
br_handle_frame+0x4c9/0x940 net/bridge/br_input.c:417
__netif_receive_skb_core+0xa8a/0x21e0 net/core/dev.c:5417
__netif_receive_skb_one_core net/core/dev.c:5521 [inline]
__netif_receive_skb+0x57/0x1b0 net/core/dev.c:5637
process_backlog+0x21f/0x380 net/core/dev.c:5965
__napi_poll+0x60/0x3b0 net/core/dev.c:6527
napi_poll net/core/dev.c:6594 [inline]
net_rx_action+0x32b/0x750 net/core/dev.c:6727
__do_softirq+0xc1/0x265 kernel/softirq.c:553
run_ksoftirqd+0x17/0x20 kernel/softirq.c:921
smpboot_thread_fn+0x30a/0x4a0 kernel/smpboot.c:164
kthread+0x1d7/0x210 kernel/kthread.c:388
ret_from_fork+0x48/0x60 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304
read-write to 0xffff8881374b2178 of 8 bytes by interrupt on cpu 0:
br_handle_frame_finish+0xd4f/0xef0 net/bridge/br_input.c:189
br_nf_hook_thresh+0x1ed/0x220
br_nf_pre_routing_finish_ipv6+0x50f/0x540
NF_HOOK include/linux/netfilter.h:304 [inline]
br_nf_pre_routing_ipv6+0x1e3/0x2a0 net/bridge/br_netfilter_ipv6.c:178
br_nf_pre_routing+0x526/0xba0 net/bridge/br_netfilter_hooks.c:508
nf_hook_entry_hookfn include/linux/netfilter.h:144 [inline]
nf_hook_bridge_pre net/bridge/br_input.c:272 [inline]
br_handle_frame+0x4c9/0x940 net/bridge/br_input.c:417
__netif_receive_skb_core+0xa8a/0x21e0 net/core/dev.c:5417
__netif_receive_skb_one_core net/core/dev.c:5521 [inline]
__netif_receive_skb+0x57/0x1b0 net/core/dev.c:5637
process_backlog+0x21f/0x380 net/core/dev.c:5965
__napi_poll+0x60/0x3b0 net/core/dev.c:6527
napi_poll net/core/dev.c:6594 [inline]
net_rx_action+0x32b/0x750 net/core/dev.c:6727
__do_softirq+0xc1/0x265 kernel/softirq.c:553
do_softirq+0x5e/0x90 kernel/softirq.c:454
__local_bh_enable_ip+0x64/0x70 kernel/softirq.c:381
__raw_spin_unlock_bh include/linux/spinlock_api_smp.h:167 [inline]
_raw_spin_unlock_bh+0x36/0x40 kernel/locking/spinlock.c:210
spin_unlock_bh include/linux/spinlock.h:396 [inline]
batadv_tt_local_purge+0x1a8/0x1f0 net/batman-adv/translation-table.c:1356
batadv_tt_purge+0x2b/0x630 net/batman-adv/translation-table.c:3560
process_one_work kernel/workqueue.c:2630 [inline]
process_scheduled_works+0x5b8/0xa30 kernel/workqueue.c:2703
worker_thread+0x525/0x730 kernel/workqueue.c:2784
kthread+0x1d7/0x210 kernel/kthread.c:388
ret_from_fork+0x48/0x60 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304
value changed: 0x00000000000d7190 -> 0x00000000000d7191
Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 14848 Comm: kworker/u4:11 Not tainted 6.6.0-rc1-syzkaller-00236-gad8a69f361b9 #0 |
| In the Linux kernel, the following vulnerability has been resolved:
x86/sgx: Resolves SECS reclaim vs. page fault for EAUG race
The SGX EPC reclaimer (ksgxd) may reclaim the SECS EPC page for an
enclave and set secs.epc_page to NULL. The SECS page is used for EAUG
and ELDU in the SGX page fault handler. However, the NULL check for
secs.epc_page is only done for ELDU, not EAUG before being used.
Fix this by doing the same NULL check and reloading of the SECS page as
needed for both EAUG and ELDU.
The SECS page holds global enclave metadata. It can only be reclaimed
when there are no other enclave pages remaining. At that point,
virtually nothing can be done with the enclave until the SECS page is
paged back in.
An enclave can not run nor generate page faults without a resident SECS
page. But it is still possible for a #PF for a non-SECS page to race
with paging out the SECS page: when the last resident non-SECS page A
triggers a #PF in a non-resident page B, and then page A and the SECS
both are paged out before the #PF on B is handled.
Hitting this bug requires that race triggered with a #PF for EAUG.
Following is a trace when it happens.
BUG: kernel NULL pointer dereference, address: 0000000000000000
RIP: 0010:sgx_encl_eaug_page+0xc7/0x210
Call Trace:
? __kmem_cache_alloc_node+0x16a/0x440
? xa_load+0x6e/0xa0
sgx_vma_fault+0x119/0x230
__do_fault+0x36/0x140
do_fault+0x12f/0x400
__handle_mm_fault+0x728/0x1110
handle_mm_fault+0x105/0x310
do_user_addr_fault+0x1ee/0x750
? __this_cpu_preempt_check+0x13/0x20
exc_page_fault+0x76/0x180
asm_exc_page_fault+0x27/0x30 |
| In the Linux kernel, the following vulnerability has been resolved:
spi: sun6i: fix race between DMA RX transfer completion and RX FIFO drain
Previously the transfer complete IRQ immediately drained to RX FIFO to
read any data remaining in FIFO to the RX buffer. This behaviour is
correct when dealing with SPI in interrupt mode. However in DMA mode the
transfer complete interrupt still fires as soon as all bytes to be
transferred have been stored in the FIFO. At that point data in the FIFO
still needs to be picked up by the DMA engine. Thus the drain procedure
and DMA engine end up racing to read from RX FIFO, corrupting any data
read. Additionally the RX buffer pointer is never adjusted according to
DMA progress in DMA mode, thus calling the RX FIFO drain procedure in DMA
mode is a bug.
Fix corruptions in DMA RX mode by draining RX FIFO only in interrupt mode.
Also wait for completion of RX DMA when in DMA mode before returning to
ensure all data has been copied to the supplied memory buffer. |
