In the Linux kernel, the following vulnerability has been resolved:
pinctrl: mcp23s08: Disable all pin interrupts during probe
A chip being probed may have the interrupt-on-change feature enabled on
some of its pins, for example after a reboot. This can cause the chip to
generate interrupts for pins that don't have a registered nested handler,
which leads to a kernel crash such as below:
[ 7.928897] Unable to handle kernel read from unreadable memory at virtual address 00000000000000ac
[ 7.932314] Mem abort info:
[ 7.935081] ESR = 0x0000000096000004
[ 7.938808] EC = 0x25: DABT (current EL), IL = 32 bits
[ 7.944094] SET = 0, FnV = 0
[ 7.947127] EA = 0, S1PTW = 0
[ 7.950247] FSC = 0x04: level 0 translation fault
[ 7.955101] Data abort info:
[ 7.957961] ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
[ 7.963421] CM = 0, WnR = 0, TnD = 0, TagAccess = 0
[ 7.968447] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[ 7.973734] user pgtable: 4k pages, 48-bit VAs, pgdp=00000000089b7000
[ 7.980148] [00000000000000ac] pgd=0000000000000000, p4d=0000000000000000
[ 7.986913] Internal error: Oops: 0000000096000004 [#1] SMP
[ 7.992545] Modules linked in:
[ 8.073678] CPU: 0 UID: 0 PID: 81 Comm: irq/18-4-0025 Not tainted 7.0.0-rc6-gd2b5a1f931c8-dirty #199
[ 8.073689] Hardware name: Khadas VIM3 (DT)
[ 8.073692] pstate: 604000c5 (nZCv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[ 8.094639] pc : _raw_spin_lock_irq+0x40/0x80
[ 8.098970] lr : handle_nested_irq+0x2c/0x168
[ 8.098979] sp : ffff800082b2bd20
[ 8.106599] x29: ffff800082b2bd20 x28: ffff800080107920 x27: ffff800080104d88
[ 8.106611] x26: ffff000003298080 x25: 0000000000000001 x24: 000000000000ff00
[ 8.113707] x23: 0000000000000001 x22: 0000000000000000 x21: 000000000000000e
[ 8.120850] x20: 0000000000000000 x19: 00000000000000ac x18: 0000000000000000
[ 8.135046] x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000
[ 8.135062] x14: ffff800081567ea8 x13: ffffffffffffffff x12: 0000000000000000
[ 8.135070] x11: 00000000000000c0 x10: 0000000000000b60 x9 : ffff800080109e0c
[ 8.135078] x8 : 1fffe0000069dbc1 x7 : 0000000000000001 x6 : ffff0000034ede00
[ 8.135086] x5 : 0000000000000000 x4 : ffff0000034ede08 x3 : 0000000000000001
[ 8.163460] x2 : 0000000000000000 x1 : 0000000000000001 x0 : 00000000000000ac
[ 8.170560] Call trace:
[ 8.180094] _raw_spin_lock_irq+0x40/0x80 (P)
[ 8.184443] mcp23s08_irq+0x248/0x358
[ 8.184462] irq_thread_fn+0x34/0xb8
[ 8.184470] irq_thread+0x1a4/0x310
[ 8.195093] kthread+0x13c/0x150
[ 8.198309] ret_from_fork+0x10/0x20
[ 8.201850] Code: d65f03c0 d2800002 52800023 f9800011 (885ffc01)
[ 8.207931] ---[ end trace 0000000000000000 ]---
This issue has always been present, but has been latent until commit
"f9f4fda15e72" ("pinctrl: mcp23s08: init reg_defaults from HW at probe and
switch cache type"), which correctly removed reg_defaults from the regmap
and as a side effect changed the behavior of the interrupt handler so that
the real value of the MCP_GPINTEN register is now being read from the chip
instead of using a bogus 0 default value; a non-zero value for this
register can trigger the invocation of a nested handler which may not exist
(yet).
Fix this issue by disabling all pin interrupts during initialization.
pinctrl: mcp23s08: Disable all pin interrupts during probe
A chip being probed may have the interrupt-on-change feature enabled on
some of its pins, for example after a reboot. This can cause the chip to
generate interrupts for pins that don't have a registered nested handler,
which leads to a kernel crash such as below:
[ 7.928897] Unable to handle kernel read from unreadable memory at virtual address 00000000000000ac
[ 7.932314] Mem abort info:
[ 7.935081] ESR = 0x0000000096000004
[ 7.938808] EC = 0x25: DABT (current EL), IL = 32 bits
[ 7.944094] SET = 0, FnV = 0
[ 7.947127] EA = 0, S1PTW = 0
[ 7.950247] FSC = 0x04: level 0 translation fault
[ 7.955101] Data abort info:
[ 7.957961] ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
[ 7.963421] CM = 0, WnR = 0, TnD = 0, TagAccess = 0
[ 7.968447] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[ 7.973734] user pgtable: 4k pages, 48-bit VAs, pgdp=00000000089b7000
[ 7.980148] [00000000000000ac] pgd=0000000000000000, p4d=0000000000000000
[ 7.986913] Internal error: Oops: 0000000096000004 [#1] SMP
[ 7.992545] Modules linked in:
[ 8.073678] CPU: 0 UID: 0 PID: 81 Comm: irq/18-4-0025 Not tainted 7.0.0-rc6-gd2b5a1f931c8-dirty #199
[ 8.073689] Hardware name: Khadas VIM3 (DT)
[ 8.073692] pstate: 604000c5 (nZCv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[ 8.094639] pc : _raw_spin_lock_irq+0x40/0x80
[ 8.098970] lr : handle_nested_irq+0x2c/0x168
[ 8.098979] sp : ffff800082b2bd20
[ 8.106599] x29: ffff800082b2bd20 x28: ffff800080107920 x27: ffff800080104d88
[ 8.106611] x26: ffff000003298080 x25: 0000000000000001 x24: 000000000000ff00
[ 8.113707] x23: 0000000000000001 x22: 0000000000000000 x21: 000000000000000e
[ 8.120850] x20: 0000000000000000 x19: 00000000000000ac x18: 0000000000000000
[ 8.135046] x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000
[ 8.135062] x14: ffff800081567ea8 x13: ffffffffffffffff x12: 0000000000000000
[ 8.135070] x11: 00000000000000c0 x10: 0000000000000b60 x9 : ffff800080109e0c
[ 8.135078] x8 : 1fffe0000069dbc1 x7 : 0000000000000001 x6 : ffff0000034ede00
[ 8.135086] x5 : 0000000000000000 x4 : ffff0000034ede08 x3 : 0000000000000001
[ 8.163460] x2 : 0000000000000000 x1 : 0000000000000001 x0 : 00000000000000ac
[ 8.170560] Call trace:
[ 8.180094] _raw_spin_lock_irq+0x40/0x80 (P)
[ 8.184443] mcp23s08_irq+0x248/0x358
[ 8.184462] irq_thread_fn+0x34/0xb8
[ 8.184470] irq_thread+0x1a4/0x310
[ 8.195093] kthread+0x13c/0x150
[ 8.198309] ret_from_fork+0x10/0x20
[ 8.201850] Code: d65f03c0 d2800002 52800023 f9800011 (885ffc01)
[ 8.207931] ---[ end trace 0000000000000000 ]---
This issue has always been present, but has been latent until commit
"f9f4fda15e72" ("pinctrl: mcp23s08: init reg_defaults from HW at probe and
switch cache type"), which correctly removed reg_defaults from the regmap
and as a side effect changed the behavior of the interrupt handler so that
the real value of the MCP_GPINTEN register is now being read from the chip
instead of using a bogus 0 default value; a non-zero value for this
register can trigger the invocation of a nested handler which may not exist
(yet).
Fix this issue by disabling all pin interrupts during initialization.
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Wed, 06 May 2026 11:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-787 |
Wed, 06 May 2026 09:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: pinctrl: mcp23s08: Disable all pin interrupts during probe A chip being probed may have the interrupt-on-change feature enabled on some of its pins, for example after a reboot. This can cause the chip to generate interrupts for pins that don't have a registered nested handler, which leads to a kernel crash such as below: [ 7.928897] Unable to handle kernel read from unreadable memory at virtual address 00000000000000ac [ 7.932314] Mem abort info: [ 7.935081] ESR = 0x0000000096000004 [ 7.938808] EC = 0x25: DABT (current EL), IL = 32 bits [ 7.944094] SET = 0, FnV = 0 [ 7.947127] EA = 0, S1PTW = 0 [ 7.950247] FSC = 0x04: level 0 translation fault [ 7.955101] Data abort info: [ 7.957961] ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000 [ 7.963421] CM = 0, WnR = 0, TnD = 0, TagAccess = 0 [ 7.968447] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 [ 7.973734] user pgtable: 4k pages, 48-bit VAs, pgdp=00000000089b7000 [ 7.980148] [00000000000000ac] pgd=0000000000000000, p4d=0000000000000000 [ 7.986913] Internal error: Oops: 0000000096000004 [#1] SMP [ 7.992545] Modules linked in: [ 8.073678] CPU: 0 UID: 0 PID: 81 Comm: irq/18-4-0025 Not tainted 7.0.0-rc6-gd2b5a1f931c8-dirty #199 [ 8.073689] Hardware name: Khadas VIM3 (DT) [ 8.073692] pstate: 604000c5 (nZCv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 8.094639] pc : _raw_spin_lock_irq+0x40/0x80 [ 8.098970] lr : handle_nested_irq+0x2c/0x168 [ 8.098979] sp : ffff800082b2bd20 [ 8.106599] x29: ffff800082b2bd20 x28: ffff800080107920 x27: ffff800080104d88 [ 8.106611] x26: ffff000003298080 x25: 0000000000000001 x24: 000000000000ff00 [ 8.113707] x23: 0000000000000001 x22: 0000000000000000 x21: 000000000000000e [ 8.120850] x20: 0000000000000000 x19: 00000000000000ac x18: 0000000000000000 [ 8.135046] x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000 [ 8.135062] x14: ffff800081567ea8 x13: ffffffffffffffff x12: 0000000000000000 [ 8.135070] x11: 00000000000000c0 x10: 0000000000000b60 x9 : ffff800080109e0c [ 8.135078] x8 : 1fffe0000069dbc1 x7 : 0000000000000001 x6 : ffff0000034ede00 [ 8.135086] x5 : 0000000000000000 x4 : ffff0000034ede08 x3 : 0000000000000001 [ 8.163460] x2 : 0000000000000000 x1 : 0000000000000001 x0 : 00000000000000ac [ 8.170560] Call trace: [ 8.180094] _raw_spin_lock_irq+0x40/0x80 (P) [ 8.184443] mcp23s08_irq+0x248/0x358 [ 8.184462] irq_thread_fn+0x34/0xb8 [ 8.184470] irq_thread+0x1a4/0x310 [ 8.195093] kthread+0x13c/0x150 [ 8.198309] ret_from_fork+0x10/0x20 [ 8.201850] Code: d65f03c0 d2800002 52800023 f9800011 (885ffc01) [ 8.207931] ---[ end trace 0000000000000000 ]--- This issue has always been present, but has been latent until commit "f9f4fda15e72" ("pinctrl: mcp23s08: init reg_defaults from HW at probe and switch cache type"), which correctly removed reg_defaults from the regmap and as a side effect changed the behavior of the interrupt handler so that the real value of the MCP_GPINTEN register is now being read from the chip instead of using a bogus 0 default value; a non-zero value for this register can trigger the invocation of a nested handler which may not exist (yet). Fix this issue by disabling all pin interrupts during initialization. | |
| Title | pinctrl: mcp23s08: Disable all pin interrupts during probe | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
Projects
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Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-05-06T07:40:21.303Z
Reserved: 2026-05-01T14:12:55.983Z
Link: CVE-2026-43087
No data.
Status : Awaiting Analysis
Published: 2026-05-06T10:16:21.963
Modified: 2026-05-06T13:08:07.970
Link: CVE-2026-43087
No data.
OpenCVE Enrichment
Updated: 2026-05-06T11:45:02Z
Weaknesses