| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
spi: don't unoptimize message in spi_async()
Calling spi_maybe_unoptimize_message() in spi_async() is wrong because
the message is likely to be in the queue and not transferred yet. This
can corrupt the message while it is being used by the controller driver.
spi_maybe_unoptimize_message() is already called in the correct place
in spi_finalize_current_message() to balance the call to
spi_maybe_optimize_message() in spi_async(). |
| In the Linux kernel, the following vulnerability has been resolved:
usb: gadget: configfs: Prevent OOB read/write in usb_string_copy()
Userspace provided string 's' could trivially have the length zero. Left
unchecked this will firstly result in an OOB read in the form
`if (str[0 - 1] == '\n') followed closely by an OOB write in the form
`str[0 - 1] = '\0'`.
There is already a validating check to catch strings that are too long.
Let's supply an additional check for invalid strings that are too short. |
| In the Linux kernel, the following vulnerability has been resolved:
s390/mm: Add NULL pointer check to crst_table_free() base_crst_free()
crst_table_free() used to work with NULL pointers before the conversion
to ptdescs. Since crst_table_free() can be called with a NULL pointer
(error handling in crst_table_upgrade() add an explicit check.
Also add the same check to base_crst_free() for consistency reasons.
In real life this should not happen, since order two GFP_KERNEL
allocations will not fail, unless FAIL_PAGE_ALLOC is enabled and used. |
| In the Linux kernel, the following vulnerability has been resolved:
filemap: replace pte_offset_map() with pte_offset_map_nolock()
The vmf->ptl in filemap_fault_recheck_pte_none() is still set from
handle_pte_fault(). But at the same time, we did a pte_unmap(vmf->pte).
After a pte_unmap(vmf->pte) unmap and rcu_read_unlock(), the page table
may be racily changed and vmf->ptl maybe fails to protect the actual page
table. Fix this by replacing pte_offset_map() with
pte_offset_map_nolock().
As David said, the PTL pointer might be stale so if we continue to use
it infilemap_fault_recheck_pte_none(), it might trigger UAF. Also, if
the PTL fails, the issue fixed by commit 58f327f2ce80 ("filemap: avoid
unnecessary major faults in filemap_fault()") might reappear. |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: mt76: replace skb_put with skb_put_zero
Avoid potentially reusing uninitialized data |
| In the Linux kernel, the following vulnerability has been resolved:
cachefiles: add consistency check for copen/cread
This prevents malicious processes from completing random copen/cread
requests and crashing the system. Added checks are listed below:
* Generic, copen can only complete open requests, and cread can only
complete read requests.
* For copen, ondemand_id must not be 0, because this indicates that the
request has not been read by the daemon.
* For cread, the object corresponding to fd and req should be the same. |
| In the Linux kernel, the following vulnerability has been resolved:
hfsplus: fix uninit-value in copy_name
[syzbot reported]
BUG: KMSAN: uninit-value in sized_strscpy+0xc4/0x160
sized_strscpy+0xc4/0x160
copy_name+0x2af/0x320 fs/hfsplus/xattr.c:411
hfsplus_listxattr+0x11e9/0x1a50 fs/hfsplus/xattr.c:750
vfs_listxattr fs/xattr.c:493 [inline]
listxattr+0x1f3/0x6b0 fs/xattr.c:840
path_listxattr fs/xattr.c:864 [inline]
__do_sys_listxattr fs/xattr.c:876 [inline]
__se_sys_listxattr fs/xattr.c:873 [inline]
__x64_sys_listxattr+0x16b/0x2f0 fs/xattr.c:873
x64_sys_call+0x2ba0/0x3b50 arch/x86/include/generated/asm/syscalls_64.h:195
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Uninit was created at:
slab_post_alloc_hook mm/slub.c:3877 [inline]
slab_alloc_node mm/slub.c:3918 [inline]
kmalloc_trace+0x57b/0xbe0 mm/slub.c:4065
kmalloc include/linux/slab.h:628 [inline]
hfsplus_listxattr+0x4cc/0x1a50 fs/hfsplus/xattr.c:699
vfs_listxattr fs/xattr.c:493 [inline]
listxattr+0x1f3/0x6b0 fs/xattr.c:840
path_listxattr fs/xattr.c:864 [inline]
__do_sys_listxattr fs/xattr.c:876 [inline]
__se_sys_listxattr fs/xattr.c:873 [inline]
__x64_sys_listxattr+0x16b/0x2f0 fs/xattr.c:873
x64_sys_call+0x2ba0/0x3b50 arch/x86/include/generated/asm/syscalls_64.h:195
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
[Fix]
When allocating memory to strbuf, initialize memory to 0. |
| In the Linux kernel, the following vulnerability has been resolved:
udp: Set SOCK_RCU_FREE earlier in udp_lib_get_port().
syzkaller triggered the warning [0] in udp_v4_early_demux().
In udp_v[46]_early_demux() and sk_lookup(), we do not touch the refcount
of the looked-up sk and use sock_pfree() as skb->destructor, so we check
SOCK_RCU_FREE to ensure that the sk is safe to access during the RCU grace
period.
Currently, SOCK_RCU_FREE is flagged for a bound socket after being put
into the hash table. Moreover, the SOCK_RCU_FREE check is done too early
in udp_v[46]_early_demux() and sk_lookup(), so there could be a small race
window:
CPU1 CPU2
---- ----
udp_v4_early_demux() udp_lib_get_port()
| |- hlist_add_head_rcu()
|- sk = __udp4_lib_demux_lookup() |
|- DEBUG_NET_WARN_ON_ONCE(sk_is_refcounted(sk));
`- sock_set_flag(sk, SOCK_RCU_FREE)
We had the same bug in TCP and fixed it in commit 871019b22d1b ("net:
set SOCK_RCU_FREE before inserting socket into hashtable").
Let's apply the same fix for UDP.
[0]:
WARNING: CPU: 0 PID: 11198 at net/ipv4/udp.c:2599 udp_v4_early_demux+0x481/0xb70 net/ipv4/udp.c:2599
Modules linked in:
CPU: 0 PID: 11198 Comm: syz-executor.1 Not tainted 6.9.0-g93bda33046e7 #13
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
RIP: 0010:udp_v4_early_demux+0x481/0xb70 net/ipv4/udp.c:2599
Code: c5 7a 15 fe bb 01 00 00 00 44 89 e9 31 ff d3 e3 81 e3 bf ef ff ff 89 de e8 2c 74 15 fe 85 db 0f 85 02 06 00 00 e8 9f 7a 15 fe <0f> 0b e8 98 7a 15 fe 49 8d 7e 60 e8 4f 39 2f fe 49 c7 46 60 20 52
RSP: 0018:ffffc9000ce3fa58 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff8318c92c
RDX: ffff888036ccde00 RSI: ffffffff8318c2f1 RDI: 0000000000000001
RBP: ffff88805a2dd6e0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0001ffffffffffff R12: ffff88805a2dd680
R13: 0000000000000007 R14: ffff88800923f900 R15: ffff88805456004e
FS: 00007fc449127640(0000) GS:ffff88807dc00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc449126e38 CR3: 000000003de4b002 CR4: 0000000000770ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
PKRU: 55555554
Call Trace:
<TASK>
ip_rcv_finish_core.constprop.0+0xbdd/0xd20 net/ipv4/ip_input.c:349
ip_rcv_finish+0xda/0x150 net/ipv4/ip_input.c:447
NF_HOOK include/linux/netfilter.h:314 [inline]
NF_HOOK include/linux/netfilter.h:308 [inline]
ip_rcv+0x16c/0x180 net/ipv4/ip_input.c:569
__netif_receive_skb_one_core+0xb3/0xe0 net/core/dev.c:5624
__netif_receive_skb+0x21/0xd0 net/core/dev.c:5738
netif_receive_skb_internal net/core/dev.c:5824 [inline]
netif_receive_skb+0x271/0x300 net/core/dev.c:5884
tun_rx_batched drivers/net/tun.c:1549 [inline]
tun_get_user+0x24db/0x2c50 drivers/net/tun.c:2002
tun_chr_write_iter+0x107/0x1a0 drivers/net/tun.c:2048
new_sync_write fs/read_write.c:497 [inline]
vfs_write+0x76f/0x8d0 fs/read_write.c:590
ksys_write+0xbf/0x190 fs/read_write.c:643
__do_sys_write fs/read_write.c:655 [inline]
__se_sys_write fs/read_write.c:652 [inline]
__x64_sys_write+0x41/0x50 fs/read_write.c:652
x64_sys_call+0xe66/0x1990 arch/x86/include/generated/asm/syscalls_64.h:2
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x4b/0x110 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x4b/0x53
RIP: 0033:0x7fc44a68bc1f
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 e9 cf f5 ff 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 3c d0 f5 ff 48
RSP: 002b:00007fc449126c90 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00000000004bc050 RCX: 00007fc44a68bc1f
R
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
nilfs2: fix kernel bug on rename operation of broken directory
Syzbot reported that in rename directory operation on broken directory on
nilfs2, __block_write_begin_int() called to prepare block write may fail
BUG_ON check for access exceeding the folio/page size.
This is because nilfs_dotdot(), which gets parent directory reference
entry ("..") of the directory to be moved or renamed, does not check
consistency enough, and may return location exceeding folio/page size for
broken directories.
Fix this issue by checking required directory entries ("." and "..") in
the first chunk of the directory in nilfs_dotdot(). |
| In the Linux kernel, the following vulnerability has been resolved:
mm: vmalloc: check if a hash-index is in cpu_possible_mask
The problem is that there are systems where cpu_possible_mask has gaps
between set CPUs, for example SPARC. In this scenario addr_to_vb_xa()
hash function can return an index which accesses to not-possible and not
setup CPU area using per_cpu() macro. This results in an oops on SPARC.
A per-cpu vmap_block_queue is also used as hash table, incorrectly
assuming the cpu_possible_mask has no gaps. Fix it by adjusting an index
to a next possible CPU. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu: change vm->task_info handling
This patch changes the handling and lifecycle of vm->task_info object.
The major changes are:
- vm->task_info is a dynamically allocated ptr now, and its uasge is
reference counted.
- introducing two new helper funcs for task_info lifecycle management
- amdgpu_vm_get_task_info: reference counts up task_info before
returning this info
- amdgpu_vm_put_task_info: reference counts down task_info
- last put to task_info() frees task_info from the vm.
This patch also does logistical changes required for existing usage
of vm->task_info.
V2: Do not block all the prints when task_info not found (Felix)
V3: Fixed review comments from Felix
- Fix wrong indentation
- No debug message for -ENOMEM
- Add NULL check for task_info
- Do not duplicate the debug messages (ti vs no ti)
- Get first reference of task_info in vm_init(), put last
in vm_fini()
V4: Fixed review comments from Felix
- fix double reference increment in create_task_info
- change amdgpu_vm_get_task_info_pasid
- additional changes in amdgpu_gem.c while porting |
| In the Linux kernel, the following vulnerability has been resolved:
tcp: avoid too many retransmit packets
If a TCP socket is using TCP_USER_TIMEOUT, and the other peer
retracted its window to zero, tcp_retransmit_timer() can
retransmit a packet every two jiffies (2 ms for HZ=1000),
for about 4 minutes after TCP_USER_TIMEOUT has 'expired'.
The fix is to make sure tcp_rtx_probe0_timed_out() takes
icsk->icsk_user_timeout into account.
Before blamed commit, the socket would not timeout after
icsk->icsk_user_timeout, but would use standard exponential
backoff for the retransmits.
Also worth noting that before commit e89688e3e978 ("net: tcp:
fix unexcepted socket die when snd_wnd is 0"), the issue
would last 2 minutes instead of 4. |
| In the Linux kernel, the following vulnerability has been resolved:
net: ena: Add validation for completion descriptors consistency
Validate that `first` flag is set only for the first
descriptor in multi-buffer packets.
In case of an invalid descriptor, a reset will occur.
A new reset reason for RX data corruption has been added. |
| In the Linux kernel, the following vulnerability has been resolved:
dmaengine: ti: k3-udma-glue: Fix of_k3_udma_glue_parse_chn_by_id()
The of_k3_udma_glue_parse_chn_by_id() helper function erroneously
invokes "of_node_put()" on the "udmax_np" device-node passed to it,
without having incremented its reference count at any point. Fix it. |
| In the Linux kernel, the following vulnerability has been resolved:
tipc: force a dst refcount before doing decryption
As it says in commit 3bc07321ccc2 ("xfrm: Force a dst refcount before
entering the xfrm type handlers"):
"Crypto requests might return asynchronous. In this case we leave the
rcu protected region, so force a refcount on the skb's destination
entry before we enter the xfrm type input/output handlers."
On TIPC decryption path it has the same problem, and skb_dst_force()
should be called before doing decryption to avoid a possible crash.
Shuang reported this issue when this warning is triggered:
[] WARNING: include/net/dst.h:337 tipc_sk_rcv+0x1055/0x1ea0 [tipc]
[] Kdump: loaded Tainted: G W --------- - - 4.18.0-496.el8.x86_64+debug
[] Workqueue: crypto cryptd_queue_worker
[] RIP: 0010:tipc_sk_rcv+0x1055/0x1ea0 [tipc]
[] Call Trace:
[] tipc_sk_mcast_rcv+0x548/0xea0 [tipc]
[] tipc_rcv+0xcf5/0x1060 [tipc]
[] tipc_aead_decrypt_done+0x215/0x2e0 [tipc]
[] cryptd_aead_crypt+0xdb/0x190
[] cryptd_queue_worker+0xed/0x190
[] process_one_work+0x93d/0x17e0 |
| In the Linux kernel, the following vulnerability has been resolved:
mm: shmem: fix getting incorrect lruvec when replacing a shmem folio
When testing shmem swapin, I encountered the warning below on my machine.
The reason is that replacing an old shmem folio with a new one causes
mem_cgroup_migrate() to clear the old folio's memcg data. As a result,
the old folio cannot get the correct memcg's lruvec needed to remove
itself from the LRU list when it is being freed. This could lead to
possible serious problems, such as LRU list crashes due to holding the
wrong LRU lock, and incorrect LRU statistics.
To fix this issue, we can fallback to use the mem_cgroup_replace_folio()
to replace the old shmem folio.
[ 5241.100311] page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5d9960
[ 5241.100317] head: order:4 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
[ 5241.100319] flags: 0x17fffe0000040068(uptodate|lru|head|swapbacked|node=0|zone=2|lastcpupid=0x3ffff)
[ 5241.100323] raw: 17fffe0000040068 fffffdffd6687948 fffffdffd69ae008 0000000000000000
[ 5241.100325] raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
[ 5241.100326] head: 17fffe0000040068 fffffdffd6687948 fffffdffd69ae008 0000000000000000
[ 5241.100327] head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
[ 5241.100328] head: 17fffe0000000204 fffffdffd6665801 ffffffffffffffff 0000000000000000
[ 5241.100329] head: 0000000a00000010 0000000000000000 00000000ffffffff 0000000000000000
[ 5241.100330] page dumped because: VM_WARN_ON_ONCE_FOLIO(!memcg && !mem_cgroup_disabled())
[ 5241.100338] ------------[ cut here ]------------
[ 5241.100339] WARNING: CPU: 19 PID: 78402 at include/linux/memcontrol.h:775 folio_lruvec_lock_irqsave+0x140/0x150
[...]
[ 5241.100374] pc : folio_lruvec_lock_irqsave+0x140/0x150
[ 5241.100375] lr : folio_lruvec_lock_irqsave+0x138/0x150
[ 5241.100376] sp : ffff80008b38b930
[...]
[ 5241.100398] Call trace:
[ 5241.100399] folio_lruvec_lock_irqsave+0x140/0x150
[ 5241.100401] __page_cache_release+0x90/0x300
[ 5241.100404] __folio_put+0x50/0x108
[ 5241.100406] shmem_replace_folio+0x1b4/0x240
[ 5241.100409] shmem_swapin_folio+0x314/0x528
[ 5241.100411] shmem_get_folio_gfp+0x3b4/0x930
[ 5241.100412] shmem_fault+0x74/0x160
[ 5241.100414] __do_fault+0x40/0x218
[ 5241.100417] do_shared_fault+0x34/0x1b0
[ 5241.100419] do_fault+0x40/0x168
[ 5241.100420] handle_pte_fault+0x80/0x228
[ 5241.100422] __handle_mm_fault+0x1c4/0x440
[ 5241.100424] handle_mm_fault+0x60/0x1f0
[ 5241.100426] do_page_fault+0x120/0x488
[ 5241.100429] do_translation_fault+0x4c/0x68
[ 5241.100431] do_mem_abort+0x48/0xa0
[ 5241.100434] el0_da+0x38/0xc0
[ 5241.100436] el0t_64_sync_handler+0x68/0xc0
[ 5241.100437] el0t_64_sync+0x14c/0x150
[ 5241.100439] ---[ end trace 0000000000000000 ]---
[baolin.wang@linux.alibaba.com: remove less helpful comments, per Matthew] |
| In the Linux kernel, the following vulnerability has been resolved:
drm/i915/dpt: Make DPT object unshrinkable
In some scenarios, the DPT object gets shrunk but
the actual framebuffer did not and thus its still
there on the DPT's vm->bound_list. Then it tries to
rewrite the PTEs via a stale CPU mapping. This causes panic.
[vsyrjala: Add TODO comment]
(cherry picked from commit 51064d471c53dcc8eddd2333c3f1c1d9131ba36c) |
| In the Linux kernel, the following vulnerability has been resolved:
vmxnet3: disable rx data ring on dma allocation failure
When vmxnet3_rq_create() fails to allocate memory for rq->data_ring.base,
the subsequent call to vmxnet3_rq_destroy_all_rxdataring does not reset
rq->data_ring.desc_size for the data ring that failed, which presumably
causes the hypervisor to reference it on packet reception.
To fix this bug, rq->data_ring.desc_size needs to be set to 0 to tell
the hypervisor to disable this feature.
[ 95.436876] kernel BUG at net/core/skbuff.c:207!
[ 95.439074] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
[ 95.440411] CPU: 7 PID: 0 Comm: swapper/7 Not tainted 6.9.3-dirty #1
[ 95.441558] Hardware name: VMware, Inc. VMware Virtual
Platform/440BX Desktop Reference Platform, BIOS 6.00 12/12/2018
[ 95.443481] RIP: 0010:skb_panic+0x4d/0x4f
[ 95.444404] Code: 4f 70 50 8b 87 c0 00 00 00 50 8b 87 bc 00 00 00 50
ff b7 d0 00 00 00 4c 8b 8f c8 00 00 00 48 c7 c7 68 e8 be 9f e8 63 58 f9
ff <0f> 0b 48 8b 14 24 48 c7 c1 d0 73 65 9f e8 a1 ff ff ff 48 8b 14 24
[ 95.447684] RSP: 0018:ffffa13340274dd0 EFLAGS: 00010246
[ 95.448762] RAX: 0000000000000089 RBX: ffff8fbbc72b02d0 RCX: 000000000000083f
[ 95.450148] RDX: 0000000000000000 RSI: 00000000000000f6 RDI: 000000000000083f
[ 95.451520] RBP: 000000000000002d R08: 0000000000000000 R09: ffffa13340274c60
[ 95.452886] R10: ffffffffa04ed468 R11: 0000000000000002 R12: 0000000000000000
[ 95.454293] R13: ffff8fbbdab3c2d0 R14: ffff8fbbdbd829e0 R15: ffff8fbbdbd809e0
[ 95.455682] FS: 0000000000000000(0000) GS:ffff8fbeefd80000(0000) knlGS:0000000000000000
[ 95.457178] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 95.458340] CR2: 00007fd0d1f650c8 CR3: 0000000115f28000 CR4: 00000000000406f0
[ 95.459791] Call Trace:
[ 95.460515] <IRQ>
[ 95.461180] ? __die_body.cold+0x19/0x27
[ 95.462150] ? die+0x2e/0x50
[ 95.462976] ? do_trap+0xca/0x110
[ 95.463973] ? do_error_trap+0x6a/0x90
[ 95.464966] ? skb_panic+0x4d/0x4f
[ 95.465901] ? exc_invalid_op+0x50/0x70
[ 95.466849] ? skb_panic+0x4d/0x4f
[ 95.467718] ? asm_exc_invalid_op+0x1a/0x20
[ 95.468758] ? skb_panic+0x4d/0x4f
[ 95.469655] skb_put.cold+0x10/0x10
[ 95.470573] vmxnet3_rq_rx_complete+0x862/0x11e0 [vmxnet3]
[ 95.471853] vmxnet3_poll_rx_only+0x36/0xb0 [vmxnet3]
[ 95.473185] __napi_poll+0x2b/0x160
[ 95.474145] net_rx_action+0x2c6/0x3b0
[ 95.475115] handle_softirqs+0xe7/0x2a0
[ 95.476122] __irq_exit_rcu+0x97/0xb0
[ 95.477109] common_interrupt+0x85/0xa0
[ 95.478102] </IRQ>
[ 95.478846] <TASK>
[ 95.479603] asm_common_interrupt+0x26/0x40
[ 95.480657] RIP: 0010:pv_native_safe_halt+0xf/0x20
[ 95.481801] Code: 22 d7 e9 54 87 01 00 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d 93 ba 3b 00 fb f4 <e9> 2c 87 01 00 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90
[ 95.485563] RSP: 0018:ffffa133400ffe58 EFLAGS: 00000246
[ 95.486882] RAX: 0000000000004000 RBX: ffff8fbbc1d14064 RCX: 0000000000000000
[ 95.488477] RDX: ffff8fbeefd80000 RSI: ffff8fbbc1d14000 RDI: 0000000000000001
[ 95.490067] RBP: ffff8fbbc1d14064 R08: ffffffffa0652260 R09: 00000000000010d3
[ 95.491683] R10: 0000000000000018 R11: ffff8fbeefdb4764 R12: ffffffffa0652260
[ 95.493389] R13: ffffffffa06522e0 R14: 0000000000000001 R15: 0000000000000000
[ 95.495035] acpi_safe_halt+0x14/0x20
[ 95.496127] acpi_idle_do_entry+0x2f/0x50
[ 95.497221] acpi_idle_enter+0x7f/0xd0
[ 95.498272] cpuidle_enter_state+0x81/0x420
[ 95.499375] cpuidle_enter+0x2d/0x40
[ 95.500400] do_idle+0x1e5/0x240
[ 95.501385] cpu_startup_entry+0x29/0x30
[ 95.502422] start_secondary+0x11c/0x140
[ 95.503454] common_startup_64+0x13e/0x141
[ 95.504466] </TASK>
[ 95.505197] Modules linked in: nft_fib_inet nft_fib_ipv4
nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6
nft_reject nft_ct nft_chain_nat nf_nat nf_conntrack nf_defrag_ip
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
parisc: Try to fix random segmentation faults in package builds
PA-RISC systems with PA8800 and PA8900 processors have had problems
with random segmentation faults for many years. Systems with earlier
processors are much more stable.
Systems with PA8800 and PA8900 processors have a large L2 cache which
needs per page flushing for decent performance when a large range is
flushed. The combined cache in these systems is also more sensitive to
non-equivalent aliases than the caches in earlier systems.
The majority of random segmentation faults that I have looked at
appear to be memory corruption in memory allocated using mmap and
malloc.
My first attempt at fixing the random faults didn't work. On
reviewing the cache code, I realized that there were two issues
which the existing code didn't handle correctly. Both relate
to cache move-in. Another issue is that the present bit in PTEs
is racy.
1) PA-RISC caches have a mind of their own and they can speculatively
load data and instructions for a page as long as there is a entry in
the TLB for the page which allows move-in. TLBs are local to each
CPU. Thus, the TLB entry for a page must be purged before flushing
the page. This is particularly important on SMP systems.
In some of the flush routines, the flush routine would be called
and then the TLB entry would be purged. This was because the flush
routine needed the TLB entry to do the flush.
2) My initial approach to trying the fix the random faults was to
try and use flush_cache_page_if_present for all flush operations.
This actually made things worse and led to a couple of hardware
lockups. It finally dawned on me that some lines weren't being
flushed because the pte check code was racy. This resulted in
random inequivalent mappings to physical pages.
The __flush_cache_page tmpalias flush sets up its own TLB entry
and it doesn't need the existing TLB entry. As long as we can find
the pte pointer for the vm page, we can get the pfn and physical
address of the page. We can also purge the TLB entry for the page
before doing the flush. Further, __flush_cache_page uses a special
TLB entry that inhibits cache move-in.
When switching page mappings, we need to ensure that lines are
removed from the cache. It is not sufficient to just flush the
lines to memory as they may come back.
This made it clear that we needed to implement all the required
flush operations using tmpalias routines. This includes flushes
for user and kernel pages.
After modifying the code to use tmpalias flushes, it became clear
that the random segmentation faults were not fully resolved. The
frequency of faults was worse on systems with a 64 MB L2 (PA8900)
and systems with more CPUs (rp4440).
The warning that I added to flush_cache_page_if_present to detect
pages that couldn't be flushed triggered frequently on some systems.
Helge and I looked at the pages that couldn't be flushed and found
that the PTE was either cleared or for a swap page. Ignoring pages
that were swapped out seemed okay but pages with cleared PTEs seemed
problematic.
I looked at routines related to pte_clear and noticed ptep_clear_flush.
The default implementation just flushes the TLB entry. However, it was
obvious that on parisc we need to flush the cache page as well. If
we don't flush the cache page, stale lines will be left in the cache
and cause random corruption. Once a PTE is cleared, there is no way
to find the physical address associated with the PTE and flush the
associated page at a later time.
I implemented an updated change with a parisc specific version of
ptep_clear_flush. It fixed the random data corruption on Helge's rp4440
and rp3440, as well as on my c8000.
At this point, I realized that I could restore the code where we only
flush in flush_cache_page_if_present if the page has been accessed.
However, for this, we also need to flush the cache when the accessed
bit is cleared in
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
ax25: Fix refcount imbalance on inbound connections
When releasing a socket in ax25_release(), we call netdev_put() to
decrease the refcount on the associated ax.25 device. However, the
execution path for accepting an incoming connection never calls
netdev_hold(). This imbalance leads to refcount errors, and ultimately
to kernel crashes.
A typical call trace for the above situation will start with one of the
following errors:
refcount_t: decrement hit 0; leaking memory.
refcount_t: underflow; use-after-free.
And will then have a trace like:
Call Trace:
<TASK>
? show_regs+0x64/0x70
? __warn+0x83/0x120
? refcount_warn_saturate+0xb2/0x100
? report_bug+0x158/0x190
? prb_read_valid+0x20/0x30
? handle_bug+0x3e/0x70
? exc_invalid_op+0x1c/0x70
? asm_exc_invalid_op+0x1f/0x30
? refcount_warn_saturate+0xb2/0x100
? refcount_warn_saturate+0xb2/0x100
ax25_release+0x2ad/0x360
__sock_release+0x35/0xa0
sock_close+0x19/0x20
[...]
On reboot (or any attempt to remove the interface), the kernel gets
stuck in an infinite loop:
unregister_netdevice: waiting for ax0 to become free. Usage count = 0
This patch corrects these issues by ensuring that we call netdev_hold()
and ax25_dev_hold() for new connections in ax25_accept(). This makes the
logic leading to ax25_accept() match the logic for ax25_bind(): in both
cases we increment the refcount, which is ultimately decremented in
ax25_release(). |
