In the Linux kernel, the following vulnerability has been resolved:
i3c: dw: avoid shift-out-of-bounds when DAA assigns no devices
On an empty bus ENTDAA assigns nothing, so cmd->rx_len (the count
of addresses left unassigned) equals master->maxdevs.
The GENMASK() index master->maxdevs - cmd->rx_len - 1 then becomes -1,
which trips up UBSAN. This happens every time on boot on a Gigabyte/AMD
server:
UBSAN: shift-out-of-bounds in drivers/i3c/master/dw-i3c-master.c:905:12
shift exponent 64 is too large for 64-bit type 'long unsigned int'
CPU: 7 UID: 0 PID: 963 Comm: (udev-worker) Not tainted 7.0.11-200.fc44.x86_64 #1 PREEMPT(lazy)
Hardware name: Giga Computing E163-Z34-AAH1-000/MZ33-DC1-000, BIOS R32_F45 04/01/2026
Call Trace:
<TASK>
dump_stack_lvl+0x5d/0x80
ubsan_epilogue+0x5/0x2b
__ubsan_handle_shift_out_of_bounds.cold+0xd7/0x1ab
dw_i3c_master_daa.cold+0x1b/0x96 [dw_i3c_master]
i3c_master_do_daa_ext.part.0+0x3e/0xf0 [i3c]
Skip the mask when no new device was assigned.
i3c: dw: avoid shift-out-of-bounds when DAA assigns no devices
On an empty bus ENTDAA assigns nothing, so cmd->rx_len (the count
of addresses left unassigned) equals master->maxdevs.
The GENMASK() index master->maxdevs - cmd->rx_len - 1 then becomes -1,
which trips up UBSAN. This happens every time on boot on a Gigabyte/AMD
server:
UBSAN: shift-out-of-bounds in drivers/i3c/master/dw-i3c-master.c:905:12
shift exponent 64 is too large for 64-bit type 'long unsigned int'
CPU: 7 UID: 0 PID: 963 Comm: (udev-worker) Not tainted 7.0.11-200.fc44.x86_64 #1 PREEMPT(lazy)
Hardware name: Giga Computing E163-Z34-AAH1-000/MZ33-DC1-000, BIOS R32_F45 04/01/2026
Call Trace:
<TASK>
dump_stack_lvl+0x5d/0x80
ubsan_epilogue+0x5/0x2b
__ubsan_handle_shift_out_of_bounds.cold+0xd7/0x1ab
dw_i3c_master_daa.cold+0x1b/0x96 [dw_i3c_master]
i3c_master_do_daa_ext.part.0+0x3e/0xf0 [i3c]
Skip the mask when no new device was assigned.
Metrics
Affected Vendors & Products
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Thu, 17 Sep 2026 16:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: i3c: dw: avoid shift-out-of-bounds when DAA assigns no devices On an empty bus ENTDAA assigns nothing, so cmd->rx_len (the count of addresses left unassigned) equals master->maxdevs. The GENMASK() index master->maxdevs - cmd->rx_len - 1 then becomes -1, which trips up UBSAN. This happens every time on boot on a Gigabyte/AMD server: UBSAN: shift-out-of-bounds in drivers/i3c/master/dw-i3c-master.c:905:12 shift exponent 64 is too large for 64-bit type 'long unsigned int' CPU: 7 UID: 0 PID: 963 Comm: (udev-worker) Not tainted 7.0.11-200.fc44.x86_64 #1 PREEMPT(lazy) Hardware name: Giga Computing E163-Z34-AAH1-000/MZ33-DC1-000, BIOS R32_F45 04/01/2026 Call Trace: <TASK> dump_stack_lvl+0x5d/0x80 ubsan_epilogue+0x5/0x2b __ubsan_handle_shift_out_of_bounds.cold+0xd7/0x1ab dw_i3c_master_daa.cold+0x1b/0x96 [dw_i3c_master] i3c_master_do_daa_ext.part.0+0x3e/0xf0 [i3c] Skip the mask when no new device was assigned. | |
| Title | i3c: dw: avoid shift-out-of-bounds when DAA assigns no devices | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
|
Projects
Sign in to view the affected projects.
MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-09-17T16:09:21.842Z
Reserved: 2026-09-11T19:38:34.809Z
Link: CVE-2026-90386
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-09-17T17:17:37.993
Modified: 2026-09-17T17:17:37.993
Link: CVE-2026-90386
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.