| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
memcg: protect concurrent access to mem_cgroup_idr
Commit 73f576c04b94 ("mm: memcontrol: fix cgroup creation failure after
many small jobs") decoupled the memcg IDs from the CSS ID space to fix the
cgroup creation failures. It introduced IDR to maintain the memcg ID
space. The IDR depends on external synchronization mechanisms for
modifications. For the mem_cgroup_idr, the idr_alloc() and idr_replace()
happen within css callback and thus are protected through cgroup_mutex
from concurrent modifications. However idr_remove() for mem_cgroup_idr
was not protected against concurrency and can be run concurrently for
different memcgs when they hit their refcnt to zero. Fix that.
We have been seeing list_lru based kernel crashes at a low frequency in
our fleet for a long time. These crashes were in different part of
list_lru code including list_lru_add(), list_lru_del() and reparenting
code. Upon further inspection, it looked like for a given object (dentry
and inode), the super_block's list_lru didn't have list_lru_one for the
memcg of that object. The initial suspicions were either the object is
not allocated through kmem_cache_alloc_lru() or somehow
memcg_list_lru_alloc() failed to allocate list_lru_one() for a memcg but
returned success. No evidence were found for these cases.
Looking more deeply, we started seeing situations where valid memcg's id
is not present in mem_cgroup_idr and in some cases multiple valid memcgs
have same id and mem_cgroup_idr is pointing to one of them. So, the most
reasonable explanation is that these situations can happen due to race
between multiple idr_remove() calls or race between
idr_alloc()/idr_replace() and idr_remove(). These races are causing
multiple memcgs to acquire the same ID and then offlining of one of them
would cleanup list_lrus on the system for all of them. Later access from
other memcgs to the list_lru cause crashes due to missing list_lru_one. |
| In the Linux kernel, the following vulnerability has been resolved:
mlxsw: spectrum_acl_erp: Fix object nesting warning
ACLs in Spectrum-2 and newer ASICs can reside in the algorithmic TCAM
(A-TCAM) or in the ordinary circuit TCAM (C-TCAM). The former can
contain more ACLs (i.e., tc filters), but the number of masks in each
region (i.e., tc chain) is limited.
In order to mitigate the effects of the above limitation, the device
allows filters to share a single mask if their masks only differ in up
to 8 consecutive bits. For example, dst_ip/25 can be represented using
dst_ip/24 with a delta of 1 bit. The C-TCAM does not have a limit on the
number of masks being used (and therefore does not support mask
aggregation), but can contain a limited number of filters.
The driver uses the "objagg" library to perform the mask aggregation by
passing it objects that consist of the filter's mask and whether the
filter is to be inserted into the A-TCAM or the C-TCAM since filters in
different TCAMs cannot share a mask.
The set of created objects is dependent on the insertion order of the
filters and is not necessarily optimal. Therefore, the driver will
periodically ask the library to compute a more optimal set ("hints") by
looking at all the existing objects.
When the library asks the driver whether two objects can be aggregated
the driver only compares the provided masks and ignores the A-TCAM /
C-TCAM indication. This is the right thing to do since the goal is to
move as many filters as possible to the A-TCAM. The driver also forbids
two identical masks from being aggregated since this can only happen if
one was intentionally put in the C-TCAM to avoid a conflict in the
A-TCAM.
The above can result in the following set of hints:
H1: {mask X, A-TCAM} -> H2: {mask Y, A-TCAM} // X is Y + delta
H3: {mask Y, C-TCAM} -> H4: {mask Z, A-TCAM} // Y is Z + delta
After getting the hints from the library the driver will start migrating
filters from one region to another while consulting the computed hints
and instructing the device to perform a lookup in both regions during
the transition.
Assuming a filter with mask X is being migrated into the A-TCAM in the
new region, the hints lookup will return H1. Since H2 is the parent of
H1, the library will try to find the object associated with it and
create it if necessary in which case another hints lookup (recursive)
will be performed. This hints lookup for {mask Y, A-TCAM} will either
return H2 or H3 since the driver passes the library an object comparison
function that ignores the A-TCAM / C-TCAM indication.
This can eventually lead to nested objects which are not supported by
the library [1].
Fix by removing the object comparison function from both the driver and
the library as the driver was the only user. That way the lookup will
only return exact matches.
I do not have a reliable reproducer that can reproduce the issue in a
timely manner, but before the fix the issue would reproduce in several
minutes and with the fix it does not reproduce in over an hour.
Note that the current usefulness of the hints is limited because they
include the C-TCAM indication and represent aggregation that cannot
actually happen. This will be addressed in net-next.
[1]
WARNING: CPU: 0 PID: 153 at lib/objagg.c:170 objagg_obj_parent_assign+0xb5/0xd0
Modules linked in:
CPU: 0 PID: 153 Comm: kworker/0:18 Not tainted 6.9.0-rc6-custom-g70fbc2c1c38b #42
Hardware name: Mellanox Technologies Ltd. MSN3700C/VMOD0008, BIOS 5.11 10/10/2018
Workqueue: mlxsw_core mlxsw_sp_acl_tcam_vregion_rehash_work
RIP: 0010:objagg_obj_parent_assign+0xb5/0xd0
[...]
Call Trace:
<TASK>
__objagg_obj_get+0x2bb/0x580
objagg_obj_get+0xe/0x80
mlxsw_sp_acl_erp_mask_get+0xb5/0xf0
mlxsw_sp_acl_atcam_entry_add+0xe8/0x3c0
mlxsw_sp_acl_tcam_entry_create+0x5e/0xa0
mlxsw_sp_acl_tcam_vchunk_migrate_one+0x16b/0x270
mlxsw_sp_acl_tcam_vregion_rehash_work+0xbe/0x510
process_one_work+0x151/0x370 |
| In the Linux kernel, the following vulnerability has been resolved:
tipc: Return non-zero value from tipc_udp_addr2str() on error
tipc_udp_addr2str() should return non-zero value if the UDP media
address is invalid. Otherwise, a buffer overflow access can occur in
tipc_media_addr_printf(). Fix this by returning 1 on an invalid UDP
media address. |
| In the Linux kernel, the following vulnerability has been resolved:
sched: act_ct: take care of padding in struct zones_ht_key
Blamed commit increased lookup key size from 2 bytes to 16 bytes,
because zones_ht_key got a struct net pointer.
Make sure rhashtable_lookup() is not using the padding bytes
which are not initialized.
BUG: KMSAN: uninit-value in rht_ptr_rcu include/linux/rhashtable.h:376 [inline]
BUG: KMSAN: uninit-value in __rhashtable_lookup include/linux/rhashtable.h:607 [inline]
BUG: KMSAN: uninit-value in rhashtable_lookup include/linux/rhashtable.h:646 [inline]
BUG: KMSAN: uninit-value in rhashtable_lookup_fast include/linux/rhashtable.h:672 [inline]
BUG: KMSAN: uninit-value in tcf_ct_flow_table_get+0x611/0x2260 net/sched/act_ct.c:329
rht_ptr_rcu include/linux/rhashtable.h:376 [inline]
__rhashtable_lookup include/linux/rhashtable.h:607 [inline]
rhashtable_lookup include/linux/rhashtable.h:646 [inline]
rhashtable_lookup_fast include/linux/rhashtable.h:672 [inline]
tcf_ct_flow_table_get+0x611/0x2260 net/sched/act_ct.c:329
tcf_ct_init+0xa67/0x2890 net/sched/act_ct.c:1408
tcf_action_init_1+0x6cc/0xb30 net/sched/act_api.c:1425
tcf_action_init+0x458/0xf00 net/sched/act_api.c:1488
tcf_action_add net/sched/act_api.c:2061 [inline]
tc_ctl_action+0x4be/0x19d0 net/sched/act_api.c:2118
rtnetlink_rcv_msg+0x12fc/0x1410 net/core/rtnetlink.c:6647
netlink_rcv_skb+0x375/0x650 net/netlink/af_netlink.c:2550
rtnetlink_rcv+0x34/0x40 net/core/rtnetlink.c:6665
netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline]
netlink_unicast+0xf52/0x1260 net/netlink/af_netlink.c:1357
netlink_sendmsg+0x10da/0x11e0 net/netlink/af_netlink.c:1901
sock_sendmsg_nosec net/socket.c:730 [inline]
__sock_sendmsg+0x30f/0x380 net/socket.c:745
____sys_sendmsg+0x877/0xb60 net/socket.c:2597
___sys_sendmsg+0x28d/0x3c0 net/socket.c:2651
__sys_sendmsg net/socket.c:2680 [inline]
__do_sys_sendmsg net/socket.c:2689 [inline]
__se_sys_sendmsg net/socket.c:2687 [inline]
__x64_sys_sendmsg+0x307/0x4a0 net/socket.c:2687
x64_sys_call+0x2dd6/0x3c10 arch/x86/include/generated/asm/syscalls_64.h:47
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Local variable key created at:
tcf_ct_flow_table_get+0x4a/0x2260 net/sched/act_ct.c:324
tcf_ct_init+0xa67/0x2890 net/sched/act_ct.c:1408 |
| In the Linux kernel, the following vulnerability has been resolved:
nvmet: fix a possible leak when destroy a ctrl during qp establishment
In nvmet_sq_destroy we capture sq->ctrl early and if it is non-NULL we
know that a ctrl was allocated (in the admin connect request handler)
and we need to release pending AERs, clear ctrl->sqs and sq->ctrl
(for nvme-loop primarily), and drop the final reference on the ctrl.
However, a small window is possible where nvmet_sq_destroy starts (as
a result of the client giving up and disconnecting) concurrently with
the nvme admin connect cmd (which may be in an early stage). But *before*
kill_and_confirm of sq->ref (i.e. the admin connect managed to get an sq
live reference). In this case, sq->ctrl was allocated however after it was
captured in a local variable in nvmet_sq_destroy.
This prevented the final reference drop on the ctrl.
Solve this by re-capturing the sq->ctrl after all inflight request has
completed, where for sure sq->ctrl reference is final, and move forward
based on that.
This issue was observed in an environment with many hosts connecting
multiple ctrls simoutanuosly, creating a delay in allocating a ctrl
leading up to this race window. |
| In the Linux kernel, the following vulnerability has been resolved:
tun: add missing verification for short frame
The cited commit missed to check against the validity of the frame length
in the tun_xdp_one() path, which could cause a corrupted skb to be sent
downstack. Even before the skb is transmitted, the
tun_xdp_one-->eth_type_trans() may access the Ethernet header although it
can be less than ETH_HLEN. Once transmitted, this could either cause
out-of-bound access beyond the actual length, or confuse the underlayer
with incorrect or inconsistent header length in the skb metadata.
In the alternative path, tun_get_user() already prohibits short frame which
has the length less than Ethernet header size from being transmitted for
IFF_TAP.
This is to drop any frame shorter than the Ethernet header size just like
how tun_get_user() does.
CVE: CVE-2024-41091 |
| In the Linux kernel, the following vulnerability has been resolved:
tap: add missing verification for short frame
The cited commit missed to check against the validity of the frame length
in the tap_get_user_xdp() path, which could cause a corrupted skb to be
sent downstack. Even before the skb is transmitted, the
tap_get_user_xdp()-->skb_set_network_header() may assume the size is more
than ETH_HLEN. Once transmitted, this could either cause out-of-bound
access beyond the actual length, or confuse the underlayer with incorrect
or inconsistent header length in the skb metadata.
In the alternative path, tap_get_user() already prohibits short frame which
has the length less than Ethernet header size from being transmitted.
This is to drop any frame shorter than the Ethernet header size just like
how tap_get_user() does.
CVE: CVE-2024-41090 |
| In the Linux kernel, the following vulnerability has been resolved:
ibmvnic: Add tx check to prevent skb leak
Below is a summary of how the driver stores a reference to an skb during
transmit:
tx_buff[free_map[consumer_index]]->skb = new_skb;
free_map[consumer_index] = IBMVNIC_INVALID_MAP;
consumer_index ++;
Where variable data looks like this:
free_map == [4, IBMVNIC_INVALID_MAP, IBMVNIC_INVALID_MAP, 0, 3]
consumer_index^
tx_buff == [skb=null, skb=<ptr>, skb=<ptr>, skb=null, skb=null]
The driver has checks to ensure that free_map[consumer_index] pointed to
a valid index but there was no check to ensure that this index pointed
to an unused/null skb address. So, if, by some chance, our free_map and
tx_buff lists become out of sync then we were previously risking an
skb memory leak. This could then cause tcp congestion control to stop
sending packets, eventually leading to ETIMEDOUT.
Therefore, add a conditional to ensure that the skb address is null. If
not then warn the user (because this is still a bug that should be
patched) and free the old pointer to prevent memleak/tcp problems. |
| In the Linux kernel, the following vulnerability has been resolved:
powerpc/eeh: avoid possible crash when edev->pdev changes
If a PCI device is removed during eeh_pe_report_edev(), edev->pdev
will change and can cause a crash, hold the PCI rescan/remove lock
while taking a copy of edev->pdev->bus. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/radeon: check bo_va->bo is non-NULL before using it
The call to radeon_vm_clear_freed might clear bo_va->bo, so
we have to check it before dereferencing it. |
| In the Linux kernel, the following vulnerability has been resolved:
filelock: fix potential use-after-free in posix_lock_inode
Light Hsieh reported a KASAN UAF warning in trace_posix_lock_inode().
The request pointer had been changed earlier to point to a lock entry
that was added to the inode's list. However, before the tracepoint could
fire, another task raced in and freed that lock.
Fix this by moving the tracepoint inside the spinlock, which should
ensure that this doesn't happen. |
| 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:
net/sched: Fix UAF when resolving a clash
KASAN reports the following UAF:
BUG: KASAN: slab-use-after-free in tcf_ct_flow_table_process_conn+0x12b/0x380 [act_ct]
Read of size 1 at addr ffff888c07603600 by task handler130/6469
Call Trace:
<IRQ>
dump_stack_lvl+0x48/0x70
print_address_description.constprop.0+0x33/0x3d0
print_report+0xc0/0x2b0
kasan_report+0xd0/0x120
__asan_load1+0x6c/0x80
tcf_ct_flow_table_process_conn+0x12b/0x380 [act_ct]
tcf_ct_act+0x886/0x1350 [act_ct]
tcf_action_exec+0xf8/0x1f0
fl_classify+0x355/0x360 [cls_flower]
__tcf_classify+0x1fd/0x330
tcf_classify+0x21c/0x3c0
sch_handle_ingress.constprop.0+0x2c5/0x500
__netif_receive_skb_core.constprop.0+0xb25/0x1510
__netif_receive_skb_list_core+0x220/0x4c0
netif_receive_skb_list_internal+0x446/0x620
napi_complete_done+0x157/0x3d0
gro_cell_poll+0xcf/0x100
__napi_poll+0x65/0x310
net_rx_action+0x30c/0x5c0
__do_softirq+0x14f/0x491
__irq_exit_rcu+0x82/0xc0
irq_exit_rcu+0xe/0x20
common_interrupt+0xa1/0xb0
</IRQ>
<TASK>
asm_common_interrupt+0x27/0x40
Allocated by task 6469:
kasan_save_stack+0x38/0x70
kasan_set_track+0x25/0x40
kasan_save_alloc_info+0x1e/0x40
__kasan_krealloc+0x133/0x190
krealloc+0xaa/0x130
nf_ct_ext_add+0xed/0x230 [nf_conntrack]
tcf_ct_act+0x1095/0x1350 [act_ct]
tcf_action_exec+0xf8/0x1f0
fl_classify+0x355/0x360 [cls_flower]
__tcf_classify+0x1fd/0x330
tcf_classify+0x21c/0x3c0
sch_handle_ingress.constprop.0+0x2c5/0x500
__netif_receive_skb_core.constprop.0+0xb25/0x1510
__netif_receive_skb_list_core+0x220/0x4c0
netif_receive_skb_list_internal+0x446/0x620
napi_complete_done+0x157/0x3d0
gro_cell_poll+0xcf/0x100
__napi_poll+0x65/0x310
net_rx_action+0x30c/0x5c0
__do_softirq+0x14f/0x491
Freed by task 6469:
kasan_save_stack+0x38/0x70
kasan_set_track+0x25/0x40
kasan_save_free_info+0x2b/0x60
____kasan_slab_free+0x180/0x1f0
__kasan_slab_free+0x12/0x30
slab_free_freelist_hook+0xd2/0x1a0
__kmem_cache_free+0x1a2/0x2f0
kfree+0x78/0x120
nf_conntrack_free+0x74/0x130 [nf_conntrack]
nf_ct_destroy+0xb2/0x140 [nf_conntrack]
__nf_ct_resolve_clash+0x529/0x5d0 [nf_conntrack]
nf_ct_resolve_clash+0xf6/0x490 [nf_conntrack]
__nf_conntrack_confirm+0x2c6/0x770 [nf_conntrack]
tcf_ct_act+0x12ad/0x1350 [act_ct]
tcf_action_exec+0xf8/0x1f0
fl_classify+0x355/0x360 [cls_flower]
__tcf_classify+0x1fd/0x330
tcf_classify+0x21c/0x3c0
sch_handle_ingress.constprop.0+0x2c5/0x500
__netif_receive_skb_core.constprop.0+0xb25/0x1510
__netif_receive_skb_list_core+0x220/0x4c0
netif_receive_skb_list_internal+0x446/0x620
napi_complete_done+0x157/0x3d0
gro_cell_poll+0xcf/0x100
__napi_poll+0x65/0x310
net_rx_action+0x30c/0x5c0
__do_softirq+0x14f/0x491
The ct may be dropped if a clash has been resolved but is still passed to
the tcf_ct_flow_table_process_conn function for further usage. This issue
can be fixed by retrieving ct from skb again after confirming conntrack. |
| In the Linux kernel, the following vulnerability has been resolved:
firmware: cs_dsp: Prevent buffer overrun when processing V2 alg headers
Check that all fields of a V2 algorithm header fit into the available
firmware data buffer.
The wmfw V2 format introduced variable-length strings in the algorithm
block header. This means the overall header length is variable, and the
position of most fields varies depending on the length of the string
fields. Each field must be checked to ensure that it does not overflow
the firmware data buffer.
As this ia bugfix patch, the fixes avoid making any significant change to
the existing code. This makes it easier to review and less likely to
introduce new bugs. |
| In the Linux kernel, the following vulnerability has been resolved:
xfs: add bounds checking to xlog_recover_process_data
There is a lack of verification of the space occupied by fixed members
of xlog_op_header in the xlog_recover_process_data.
We can create a crafted image to trigger an out of bounds read by
following these steps:
1) Mount an image of xfs, and do some file operations to leave records
2) Before umounting, copy the image for subsequent steps to simulate
abnormal exit. Because umount will ensure that tail_blk and
head_blk are the same, which will result in the inability to enter
xlog_recover_process_data
3) Write a tool to parse and modify the copied image in step 2
4) Make the end of the xlog_op_header entries only 1 byte away from
xlog_rec_header->h_size
5) xlog_rec_header->h_num_logops++
6) Modify xlog_rec_header->h_crc
Fix:
Add a check to make sure there is sufficient space to access fixed members
of xlog_op_header. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix overrunning reservations in ringbuf
The BPF ring buffer internally is implemented as a power-of-2 sized circular
buffer, with two logical and ever-increasing counters: consumer_pos is the
consumer counter to show which logical position the consumer consumed the
data, and producer_pos which is the producer counter denoting the amount of
data reserved by all producers.
Each time a record is reserved, the producer that "owns" the record will
successfully advance producer counter. In user space each time a record is
read, the consumer of the data advanced the consumer counter once it finished
processing. Both counters are stored in separate pages so that from user
space, the producer counter is read-only and the consumer counter is read-write.
One aspect that simplifies and thus speeds up the implementation of both
producers and consumers is how the data area is mapped twice contiguously
back-to-back in the virtual memory, allowing to not take any special measures
for samples that have to wrap around at the end of the circular buffer data
area, because the next page after the last data page would be first data page
again, and thus the sample will still appear completely contiguous in virtual
memory.
Each record has a struct bpf_ringbuf_hdr { u32 len; u32 pg_off; } header for
book-keeping the length and offset, and is inaccessible to the BPF program.
Helpers like bpf_ringbuf_reserve() return `(void *)hdr + BPF_RINGBUF_HDR_SZ`
for the BPF program to use. Bing-Jhong and Muhammad reported that it is however
possible to make a second allocated memory chunk overlapping with the first
chunk and as a result, the BPF program is now able to edit first chunk's
header.
For example, consider the creation of a BPF_MAP_TYPE_RINGBUF map with size
of 0x4000. Next, the consumer_pos is modified to 0x3000 /before/ a call to
bpf_ringbuf_reserve() is made. This will allocate a chunk A, which is in
[0x0,0x3008], and the BPF program is able to edit [0x8,0x3008]. Now, lets
allocate a chunk B with size 0x3000. This will succeed because consumer_pos
was edited ahead of time to pass the `new_prod_pos - cons_pos > rb->mask`
check. Chunk B will be in range [0x3008,0x6010], and the BPF program is able
to edit [0x3010,0x6010]. Due to the ring buffer memory layout mentioned
earlier, the ranges [0x0,0x4000] and [0x4000,0x8000] point to the same data
pages. This means that chunk B at [0x4000,0x4008] is chunk A's header.
bpf_ringbuf_submit() / bpf_ringbuf_discard() use the header's pg_off to then
locate the bpf_ringbuf itself via bpf_ringbuf_restore_from_rec(). Once chunk
B modified chunk A's header, then bpf_ringbuf_commit() refers to the wrong
page and could cause a crash.
Fix it by calculating the oldest pending_pos and check whether the range
from the oldest outstanding record to the newest would span beyond the ring
buffer size. If that is the case, then reject the request. We've tested with
the ring buffer benchmark in BPF selftests (./benchs/run_bench_ringbufs.sh)
before/after the fix and while it seems a bit slower on some benchmarks, it
is still not significantly enough to matter. |
| 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:
ACPICA: Revert "ACPICA: avoid Info: mapping multiple BARs. Your kernel is fine."
Undo the modifications made in commit d410ee5109a1 ("ACPICA: avoid
"Info: mapping multiple BARs. Your kernel is fine.""). The initial
purpose of this commit was to stop memory mappings for operation
regions from overlapping page boundaries, as it can trigger warnings
if different page attributes are present.
However, it was found that when this situation arises, mapping
continues until the boundary's end, but there is still an attempt to
read/write the entire length of the map, leading to a NULL pointer
deference. For example, if a four-byte mapping request is made but
only one byte is mapped because it hits the current page boundary's
end, a four-byte read/write attempt is still made, resulting in a NULL
pointer deference.
Instead, map the entire length, as the ACPI specification does not
mandate that it must be within the same page boundary. It is
permissible for it to be mapped across different regions. |
| 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 |
