Linux: >> Linux Kernel >> 6.6.63 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
drm/amdkfd: Correct the migration DMA map direction
The SVM DMA device map direction should be set the same as
the DMA unmap setting, otherwise the DMA core will report
the following warning.
Before finialize this solution, there're some discussion on
the DMA mapping type(stream-based or coherent) in this KFD
migration case, followed by https://lore.kernel.org/all/04d4ab32
-45a1-4b88-86ee-fb0f35a0ca40@amd.com/T/.
As there's no dma_sync_single_for_*() in the DMA buffer accessed
that because this migration operation should be sync properly and
automatically. Give that there's might not be a performance problem
in various cache sync policy of DMA sync. Therefore, in order to
simplify the DMA direction setting alignment, let's set the DMA map
direction as BIDIRECTIONAL.
[ 150.834218] WARNING: CPU: 8 PID: 1812 at kernel/dma/debug.c:1028 check_unmap+0x1cc/0x930
[ 150.834225] Modules linked in: amdgpu(OE) amdxcp drm_exec(OE) gpu_sched drm_buddy(OE) drm_ttm_helper(OE) ttm(OE) drm_suballoc_helper(OE) drm_display_helper(OE) drm_kms_helper(OE) i2c_algo_bit rpcsec_gss_krb5 auth_rpcgss nfsv4 nfs lockd grace netfs xt_conntrack xt_MASQUERADE nf_conntrack_netlink xfrm_user xfrm_algo iptable_nat xt_addrtype iptable_filter br_netfilter nvme_fabrics overlay nfnetlink_cttimeout nfnetlink openvswitch nsh nf_conncount nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 libcrc32c bridge stp llc sch_fq_codel intel_rapl_msr amd_atl intel_rapl_common snd_hda_codec_realtek snd_hda_codec_generic snd_hda_scodec_component snd_hda_codec_hdmi snd_hda_intel snd_intel_dspcfg edac_mce_amd snd_pci_acp6x snd_hda_codec snd_acp_config snd_hda_core snd_hwdep snd_soc_acpi kvm_amd sunrpc snd_pcm kvm binfmt_misc snd_seq_midi crct10dif_pclmul snd_seq_midi_event ghash_clmulni_intel sha512_ssse3 snd_rawmidi nls_iso8859_1 sha256_ssse3 sha1_ssse3 snd_seq aesni_intel snd_seq_device crypto_simd snd_timer cryptd input_leds
[ 150.834310] wmi_bmof serio_raw k10temp rapl snd sp5100_tco ipmi_devintf soundcore ccp ipmi_msghandler cm32181 industrialio mac_hid msr parport_pc ppdev lp parport efi_pstore drm(OE) ip_tables x_tables pci_stub crc32_pclmul nvme ahci libahci i2c_piix4 r8169 nvme_core i2c_designware_pci realtek i2c_ccgx_ucsi video wmi hid_generic cdc_ether usbnet usbhid hid r8152 mii
[ 150.834354] CPU: 8 PID: 1812 Comm: rocrtst64 Tainted: G OE 6.10.0-custom #492
[ 150.834358] Hardware name: AMD Majolica-RN/Majolica-RN, BIOS RMJ1009A 06/13/2021
[ 150.834360] RIP: 0010:check_unmap+0x1cc/0x930
[ 150.834363] Code: c0 4c 89 4d c8 e8 34 bf 86 00 4c 8b 4d c8 4c 8b 45 c0 48 8b 4d b8 48 89 c6 41 57 4c 89 ea 48 c7 c7 80 49 b4 84 e8 b4 81 f3 ff <0f> 0b 48 c7 c7 04 83 ac 84 e8 76 ba fc ff 41 8b 76 4c 49 8d 7e 50
[ 150.834365] RSP: 0018:ffffaac5023739e0 EFLAGS: 00010086
[ 150.834368] RAX: 0000000000000000 RBX: ffffffff8566a2e0 RCX: 0000000000000027
[ 150.834370] RDX: ffff8f6a8f621688 RSI: 0000000000000001 RDI: ffff8f6a8f621680
[ 150.834372] RBP: ffffaac502373a30 R08: 00000000000000c9 R09: ffffaac502373850
[ 150.834373] R10: ffffaac502373848 R11: ffffffff84f46328 R12: ffffaac502373a40
[ 150.834375] R13: ffff8f6741045330 R14: ffff8f6741a77700 R15: ffffffff84ac831b
[ 150.834377] FS: 00007faf0fc94c00(0000) GS:ffff8f6a8f600000(0000) knlGS:0000000000000000
[ 150.834379] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 150.834381] CR2: 00007faf0b600020 CR3: 000000010a52e000 CR4: 0000000000350ef0
[ 150.834383] Call Trace:
[ 150.834385] <TASK>
[ 150.834387] ? show_regs+0x6d/0x80
[ 150.834393] ? __warn+0x8c/0x140
[ 150.834397] ? check_unmap+0x1cc/0x930
[ 150.834400] ? report_bug+0x193/0x1a0
[ 150.834406] ? handle_bug+0x46/0x80
[ 150.834410] ? exc_invalid_op+0x1d/0x80
[ 150.834413] ? asm_exc_invalid_op+0x1f/0x30
[ 150.834420] ? check_unmap+0x1cc/0x930
[ 150.834425] debug_dma_unmap_page+0x86/0x90
[ 150.834431] ? srso_return_thunk+0x5/0x5f
[ 150.834435]
---truncated---
CVSS Score
5.5
EPSS Score
0.0
Published
2025-01-15
In the Linux kernel, the following vulnerability has been resolved:
wifi: cfg80211: clear link ID from bitmap during link delete after clean up
Currently, during link deletion, the link ID is first removed from the
valid_links bitmap before performing any clean-up operations. However, some
functions require the link ID to remain in the valid_links bitmap. One
such example is cfg80211_cac_event(). The flow is -
nl80211_remove_link()
cfg80211_remove_link()
ieee80211_del_intf_link()
ieee80211_vif_set_links()
ieee80211_vif_update_links()
ieee80211_link_stop()
cfg80211_cac_event()
cfg80211_cac_event() requires link ID to be present but it is cleared
already in cfg80211_remove_link(). Ultimately, WARN_ON() is hit.
Therefore, clear the link ID from the bitmap only after completing the link
clean-up.
CVSS Score
3.3
EPSS Score
0.0
Published
2025-01-15
In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211: fix mbss changed flags corruption on 32 bit systems
On 32-bit systems, the size of an unsigned long is 4 bytes,
while a u64 is 8 bytes. Therefore, when using
or_each_set_bit(bit, &bits, sizeof(changed) * BITS_PER_BYTE),
the code is incorrectly searching for a bit in a 32-bit
variable that is expected to be 64 bits in size,
leading to incorrect bit finding.
Solution: Ensure that the size of the bits variable is correctly
adjusted for each architecture.
Call Trace:
? show_regs+0x54/0x58
? __warn+0x6b/0xd4
? ieee80211_link_info_change_notify+0xcc/0xd4 [mac80211]
? report_bug+0x113/0x150
? exc_overflow+0x30/0x30
? handle_bug+0x27/0x44
? exc_invalid_op+0x18/0x50
? handle_exception+0xf6/0xf6
? exc_overflow+0x30/0x30
? ieee80211_link_info_change_notify+0xcc/0xd4 [mac80211]
? exc_overflow+0x30/0x30
? ieee80211_link_info_change_notify+0xcc/0xd4 [mac80211]
? ieee80211_mesh_work+0xff/0x260 [mac80211]
? cfg80211_wiphy_work+0x72/0x98 [cfg80211]
? process_one_work+0xf1/0x1fc
? worker_thread+0x2c0/0x3b4
? kthread+0xc7/0xf0
? mod_delayed_work_on+0x4c/0x4c
? kthread_complete_and_exit+0x14/0x14
? ret_from_fork+0x24/0x38
? kthread_complete_and_exit+0x14/0x14
? ret_from_fork_asm+0xf/0x14
? entry_INT80_32+0xf0/0xf0
[restore no-op path for no changes]
CVSS Score
7.8
EPSS Score
0.0
Published
2025-01-15
In the Linux kernel, the following vulnerability has been resolved:
ila: serialize calls to nf_register_net_hooks()
syzbot found a race in ila_add_mapping() [1]
commit 031ae72825ce ("ila: call nf_unregister_net_hooks() sooner")
attempted to fix a similar issue.
Looking at the syzbot repro, we have concurrent ILA_CMD_ADD commands.
Add a mutex to make sure at most one thread is calling nf_register_net_hooks().
[1]
BUG: KASAN: slab-use-after-free in rht_key_hashfn include/linux/rhashtable.h:159 [inline]
BUG: KASAN: slab-use-after-free in __rhashtable_lookup.constprop.0+0x426/0x550 include/linux/rhashtable.h:604
Read of size 4 at addr ffff888028f40008 by task dhcpcd/5501
CPU: 1 UID: 0 PID: 5501 Comm: dhcpcd Not tainted 6.13.0-rc4-syzkaller-00054-gd6ef8b40d075 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0xc3/0x620 mm/kasan/report.c:489
kasan_report+0xd9/0x110 mm/kasan/report.c:602
rht_key_hashfn include/linux/rhashtable.h:159 [inline]
__rhashtable_lookup.constprop.0+0x426/0x550 include/linux/rhashtable.h:604
rhashtable_lookup include/linux/rhashtable.h:646 [inline]
rhashtable_lookup_fast include/linux/rhashtable.h:672 [inline]
ila_lookup_wildcards net/ipv6/ila/ila_xlat.c:127 [inline]
ila_xlat_addr net/ipv6/ila/ila_xlat.c:652 [inline]
ila_nf_input+0x1ee/0x620 net/ipv6/ila/ila_xlat.c:185
nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline]
nf_hook_slow+0xbb/0x200 net/netfilter/core.c:626
nf_hook.constprop.0+0x42e/0x750 include/linux/netfilter.h:269
NF_HOOK include/linux/netfilter.h:312 [inline]
ipv6_rcv+0xa4/0x680 net/ipv6/ip6_input.c:309
__netif_receive_skb_one_core+0x12e/0x1e0 net/core/dev.c:5672
__netif_receive_skb+0x1d/0x160 net/core/dev.c:5785
process_backlog+0x443/0x15f0 net/core/dev.c:6117
__napi_poll.constprop.0+0xb7/0x550 net/core/dev.c:6883
napi_poll net/core/dev.c:6952 [inline]
net_rx_action+0xa94/0x1010 net/core/dev.c:7074
handle_softirqs+0x213/0x8f0 kernel/softirq.c:561
__do_softirq kernel/softirq.c:595 [inline]
invoke_softirq kernel/softirq.c:435 [inline]
__irq_exit_rcu+0x109/0x170 kernel/softirq.c:662
irq_exit_rcu+0x9/0x30 kernel/softirq.c:678
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1049
CVSS Score
7.8
EPSS Score
0.0
Published
2025-01-15
In the Linux kernel, the following vulnerability has been resolved:
af_packet: fix vlan_get_protocol_dgram() vs MSG_PEEK
Blamed commit forgot MSG_PEEK case, allowing a crash [1] as found
by syzbot.
Rework vlan_get_protocol_dgram() to not touch skb at all,
so that it can be used from many cpus on the same skb.
Add a const qualifier to skb argument.
[1]
skbuff: skb_under_panic: text:ffffffff8a8ccd05 len:29 put:14 head:ffff88807fc8e400 data:ffff88807fc8e3f4 tail:0x11 end:0x140 dev:<NULL>
------------[ cut here ]------------
kernel BUG at net/core/skbuff.c:206 !
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
CPU: 1 UID: 0 PID: 5892 Comm: syz-executor883 Not tainted 6.13.0-rc4-syzkaller-00054-gd6ef8b40d075 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:skb_panic net/core/skbuff.c:206 [inline]
RIP: 0010:skb_under_panic+0x14b/0x150 net/core/skbuff.c:216
Code: 0b 8d 48 c7 c6 86 d5 25 8e 48 8b 54 24 08 8b 0c 24 44 8b 44 24 04 4d 89 e9 50 41 54 41 57 41 56 e8 5a 69 79 f7 48 83 c4 20 90 <0f> 0b 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3
RSP: 0018:ffffc900038d7638 EFLAGS: 00010282
RAX: 0000000000000087 RBX: dffffc0000000000 RCX: 609ffd18ea660600
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: ffff88802483c8d0 R08: ffffffff817f0a8c R09: 1ffff9200071ae60
R10: dffffc0000000000 R11: fffff5200071ae61 R12: 0000000000000140
R13: ffff88807fc8e400 R14: ffff88807fc8e3f4 R15: 0000000000000011
FS: 00007fbac5e006c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbac5e00d58 CR3: 000000001238e000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
skb_push+0xe5/0x100 net/core/skbuff.c:2636
vlan_get_protocol_dgram+0x165/0x290 net/packet/af_packet.c:585
packet_recvmsg+0x948/0x1ef0 net/packet/af_packet.c:3552
sock_recvmsg_nosec net/socket.c:1033 [inline]
sock_recvmsg+0x22f/0x280 net/socket.c:1055
____sys_recvmsg+0x1c6/0x480 net/socket.c:2803
___sys_recvmsg net/socket.c:2845 [inline]
do_recvmmsg+0x426/0xab0 net/socket.c:2940
__sys_recvmmsg net/socket.c:3014 [inline]
__do_sys_recvmmsg net/socket.c:3037 [inline]
__se_sys_recvmmsg net/socket.c:3030 [inline]
__x64_sys_recvmmsg+0x199/0x250 net/socket.c:3030
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
CVSS Score
5.5
EPSS Score
0.0
Published
2025-01-15
In the Linux kernel, the following vulnerability has been resolved:
af_packet: fix vlan_get_tci() vs MSG_PEEK
Blamed commit forgot MSG_PEEK case, allowing a crash [1] as found
by syzbot.
Rework vlan_get_tci() to not touch skb at all,
so that it can be used from many cpus on the same skb.
Add a const qualifier to skb argument.
[1]
skbuff: skb_under_panic: text:ffffffff8a8da482 len:32 put:14 head:ffff88807a1d5800 data:ffff88807a1d5810 tail:0x14 end:0x140 dev:<NULL>
------------[ cut here ]------------
kernel BUG at net/core/skbuff.c:206 !
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
CPU: 0 UID: 0 PID: 5880 Comm: syz-executor172 Not tainted 6.13.0-rc3-syzkaller-00762-g9268abe611b0 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:skb_panic net/core/skbuff.c:206 [inline]
RIP: 0010:skb_under_panic+0x14b/0x150 net/core/skbuff.c:216
Code: 0b 8d 48 c7 c6 9e 6c 26 8e 48 8b 54 24 08 8b 0c 24 44 8b 44 24 04 4d 89 e9 50 41 54 41 57 41 56 e8 3a 5a 79 f7 48 83 c4 20 90 <0f> 0b 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3
RSP: 0018:ffffc90003baf5b8 EFLAGS: 00010286
RAX: 0000000000000087 RBX: dffffc0000000000 RCX: 8565c1eec37aa000
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: ffff88802616fb50 R08: ffffffff817f0a4c R09: 1ffff92000775e50
R10: dffffc0000000000 R11: fffff52000775e51 R12: 0000000000000140
R13: ffff88807a1d5800 R14: ffff88807a1d5810 R15: 0000000000000014
FS: 00007fa03261f6c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd65753000 CR3: 0000000031720000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
skb_push+0xe5/0x100 net/core/skbuff.c:2636
vlan_get_tci+0x272/0x550 net/packet/af_packet.c:565
packet_recvmsg+0x13c9/0x1ef0 net/packet/af_packet.c:3616
sock_recvmsg_nosec net/socket.c:1044 [inline]
sock_recvmsg+0x22f/0x280 net/socket.c:1066
____sys_recvmsg+0x1c6/0x480 net/socket.c:2814
___sys_recvmsg net/socket.c:2856 [inline]
do_recvmmsg+0x426/0xab0 net/socket.c:2951
__sys_recvmmsg net/socket.c:3025 [inline]
__do_sys_recvmmsg net/socket.c:3048 [inline]
__se_sys_recvmmsg net/socket.c:3041 [inline]
__x64_sys_recvmmsg+0x199/0x250 net/socket.c:3041
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
CVSS Score
5.5
EPSS Score
0.0
Published
2025-01-15
In the Linux kernel, the following vulnerability has been resolved:
net: restrict SO_REUSEPORT to inet sockets
After blamed commit, crypto sockets could accidentally be destroyed
from RCU call back, as spotted by zyzbot [1].
Trying to acquire a mutex in RCU callback is not allowed.
Restrict SO_REUSEPORT socket option to inet sockets.
v1 of this patch supported TCP, UDP and SCTP sockets,
but fcnal-test.sh test needed RAW and ICMP support.
[1]
BUG: sleeping function called from invalid context at kernel/locking/mutex.c:562
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 24, name: ksoftirqd/1
preempt_count: 100, expected: 0
RCU nest depth: 0, expected: 0
1 lock held by ksoftirqd/1/24:
#0: ffffffff8e937ba0 (rcu_callback){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
#0: ffffffff8e937ba0 (rcu_callback){....}-{0:0}, at: rcu_do_batch kernel/rcu/tree.c:2561 [inline]
#0: ffffffff8e937ba0 (rcu_callback){....}-{0:0}, at: rcu_core+0xa37/0x17a0 kernel/rcu/tree.c:2823
Preemption disabled at:
[<ffffffff8161c8c8>] softirq_handle_begin kernel/softirq.c:402 [inline]
[<ffffffff8161c8c8>] handle_softirqs+0x128/0x9b0 kernel/softirq.c:537
CPU: 1 UID: 0 PID: 24 Comm: ksoftirqd/1 Not tainted 6.13.0-rc3-syzkaller-00174-ga024e377efed #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
__might_resched+0x5d4/0x780 kernel/sched/core.c:8758
__mutex_lock_common kernel/locking/mutex.c:562 [inline]
__mutex_lock+0x131/0xee0 kernel/locking/mutex.c:735
crypto_put_default_null_skcipher+0x18/0x70 crypto/crypto_null.c:179
aead_release+0x3d/0x50 crypto/algif_aead.c:489
alg_do_release crypto/af_alg.c:118 [inline]
alg_sock_destruct+0x86/0xc0 crypto/af_alg.c:502
__sk_destruct+0x58/0x5f0 net/core/sock.c:2260
rcu_do_batch kernel/rcu/tree.c:2567 [inline]
rcu_core+0xaaa/0x17a0 kernel/rcu/tree.c:2823
handle_softirqs+0x2d4/0x9b0 kernel/softirq.c:561
run_ksoftirqd+0xca/0x130 kernel/softirq.c:950
smpboot_thread_fn+0x544/0xa30 kernel/smpboot.c:164
kthread+0x2f0/0x390 kernel/kthread.c:389
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
</TASK>
CVSS Score
5.5
EPSS Score
0.0
Published
2025-01-15
In the Linux kernel, the following vulnerability has been resolved:
drm: adv7511: Fix use-after-free in adv7533_attach_dsi()
The host_node pointer was assigned and freed in adv7533_parse_dt(), and
later, adv7533_attach_dsi() uses the same. Fix this use-after-free issue
by dropping of_node_put() in adv7533_parse_dt() and calling of_node_put()
in error path of probe() and also in the remove().
CVSS Score
7.8
EPSS Score
0.0
Published
2025-01-15
In the Linux kernel, the following vulnerability has been resolved:
workqueue: Do not warn when cancelling WQ_MEM_RECLAIM work from !WQ_MEM_RECLAIM worker
After commit
746ae46c1113 ("drm/sched: Mark scheduler work queues with WQ_MEM_RECLAIM")
amdgpu started seeing the following warning:
[ ] workqueue: WQ_MEM_RECLAIM sdma0:drm_sched_run_job_work [gpu_sched] is flushing !WQ_MEM_RECLAIM events:amdgpu_device_delay_enable_gfx_off [amdgpu]
...
[ ] Workqueue: sdma0 drm_sched_run_job_work [gpu_sched]
...
[ ] Call Trace:
[ ] <TASK>
...
[ ] ? check_flush_dependency+0xf5/0x110
...
[ ] cancel_delayed_work_sync+0x6e/0x80
[ ] amdgpu_gfx_off_ctrl+0xab/0x140 [amdgpu]
[ ] amdgpu_ring_alloc+0x40/0x50 [amdgpu]
[ ] amdgpu_ib_schedule+0xf4/0x810 [amdgpu]
[ ] ? drm_sched_run_job_work+0x22c/0x430 [gpu_sched]
[ ] amdgpu_job_run+0xaa/0x1f0 [amdgpu]
[ ] drm_sched_run_job_work+0x257/0x430 [gpu_sched]
[ ] process_one_work+0x217/0x720
...
[ ] </TASK>
The intent of the verifcation done in check_flush_depedency is to ensure
forward progress during memory reclaim, by flagging cases when either a
memory reclaim process, or a memory reclaim work item is flushed from a
context not marked as memory reclaim safe.
This is correct when flushing, but when called from the
cancel(_delayed)_work_sync() paths it is a false positive because work is
either already running, or will not be running at all. Therefore
cancelling it is safe and we can relax the warning criteria by letting the
helper know of the calling context.
References: 746ae46c1113 ("drm/sched: Mark scheduler work queues with WQ_MEM_RECLAIM")
CVSS Score
5.5
EPSS Score
0.0
Published
2025-01-15
In the Linux kernel, the following vulnerability has been resolved:
pinctrl: mcp23s08: Fix sleeping in atomic context due to regmap locking
If a device uses MCP23xxx IO expander to receive IRQs, the following
bug can happen:
BUG: sleeping function called from invalid context
at kernel/locking/mutex.c:283
in_atomic(): 1, irqs_disabled(): 1, non_block: 0, ...
preempt_count: 1, expected: 0
...
Call Trace:
...
__might_resched+0x104/0x10e
__might_sleep+0x3e/0x62
mutex_lock+0x20/0x4c
regmap_lock_mutex+0x10/0x18
regmap_update_bits_base+0x2c/0x66
mcp23s08_irq_set_type+0x1ae/0x1d6
__irq_set_trigger+0x56/0x172
__setup_irq+0x1e6/0x646
request_threaded_irq+0xb6/0x160
...
We observed the problem while experimenting with a touchscreen driver which
used MCP23017 IO expander (I2C).
The regmap in the pinctrl-mcp23s08 driver uses a mutex for protection from
concurrent accesses, which is the default for regmaps without .fast_io,
.disable_locking, etc.
mcp23s08_irq_set_type() calls regmap_update_bits_base(), and the latter
locks the mutex.
However, __setup_irq() locks desc->lock spinlock before calling these
functions. As a result, the system tries to lock the mutex whole holding
the spinlock.
It seems, the internal regmap locks are not needed in this driver at all.
mcp->lock seems to protect the regmap from concurrent accesses already,
except, probably, in mcp_pinconf_get/set.
mcp23s08_irq_set_type() and mcp23s08_irq_mask/unmask() are called under
chip_bus_lock(), which calls mcp23s08_irq_bus_lock(). The latter takes
mcp->lock and enables regmap caching, so that the potentially slow I2C
accesses are deferred until chip_bus_unlock().
The accesses to the regmap from mcp23s08_probe_one() do not need additional
locking.
In all remaining places where the regmap is accessed, except
mcp_pinconf_get/set(), the driver already takes mcp->lock.
This patch adds locking in mcp_pinconf_get/set() and disables internal
locking in the regmap config. Among other things, it fixes the sleeping
in atomic context described above.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-01-15