CVE-2024-50072

x86/bugs: Use code segment selector for VERW operand

MEDIUM

5.5

CVSS Score

Published: October 29, 2024 at 12:50 AM UTC

Updated: June 17, 2026 at 08:03 AM UTC

1 product affected across 1 vendorLinux Kernel

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Severity

MEDIUM5.5

Exploit prediction

EPSS 0.2%

Description

In the Linux kernel, the following vulnerability has been resolved: x86/bugs: Use code segment selector for VERW operand Robert Gill reported below #GP in 32-bit mode when dosemu software was executing vm86() system call: general protection fault: 0000 [#1] PREEMPT SMP CPU: 4 PID: 4610 Comm: dosemu.bin Not tainted 6.6.21-gentoo-x86 #1 Hardware name: Dell Inc. PowerEdge 1950/0H723K, BIOS 2.7.0 10/30/2010 EIP: restore_all_switch_stack+0xbe/0xcf EAX: 00000000 EBX: 00000000 ECX: 00000000 EDX: 00000000 ESI: 00000000 EDI: 00000000 EBP: 00000000 ESP: ff8affdc DS: 0000 ES: 0000 FS: 0000 GS: 0033 SS: 0068 EFLAGS: 00010046 CR0: 80050033 CR2: 00c2101c CR3: 04b6d000 CR4: 000406d0 Call Trace: show_regs+0x70/0x78 die_addr+0x29/0x70 exc_general_protection+0x13c/0x348 exc_bounds+0x98/0x98 handle_exception+0x14d/0x14d exc_bounds+0x98/0x98 restore_all_switch_stack+0xbe/0xcf exc_bounds+0x98/0x98 restore_all_switch_stack+0xbe/0xcf This only happens in 32-bit mode when VERW based mitigations like MDS/RFDS are enabled. This is because segment registers with an arbitrary user value can result in #GP when executing VERW. Intel SDM vol. 2C documents the following behavior for VERW instruction: #GP(0) - If a memory operand effective address is outside the CS, DS, ES, FS, or GS segment limit. CLEAR_CPU_BUFFERS macro executes VERW instruction before returning to user space. Use %cs selector to reference VERW operand. This ensures VERW will not #GP for an arbitrary user %ds. [ mingo: Fixed the SOB chain. ]

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Linux Kernel · Linux

95%

v ≥ 6.7.95.10.215 ≤ v < 5.10.2295.10.215 ≤ v < 5.115.15.154 ≤ v < 5.15.1715.15.154 ≤ v < 5.166.1.81 ≤ v < 6.1.1166.1.81 ≤ v < 6.26.6.21 ≤ v < 6.6.586.7 ≤ v < 6.11.56.7.9 ≤ v < 6.86.8 ≤ v < 6.11.56.8 ≤ v < 6.122e3087505ddb8ba2d3d4c81306cca11e868fcdb95.10.215 5.15.15450f021f0b985629accf10481a6e89af8b970058351eca9f1fd047b500137d021f882d93f032801186.1.81 6.12 rc1 6.12 rc2 6.12 rc3 6.6.21 6.7.9a0e2dab44d22b913b4c228c8b52b2a104434b0b3ca13d8cd8dac25558da4ee8df4dc70e8e7f9d762d54de9f2a127090f2017184e8257795b487d5312

Vendor states this is fixed in 38c5fe74f3bef98f75d16effa49836d50c9b6097 (fixed)

Vendor states this is fixed in 481b477ab63c7245715a3e57ba79eb87c2dc0d02 (fixed)

Vendor states this is fixed in ada431c6c31a2c8c37991c46089af5caa23a9c6e (fixed)

Vendor states this is fixed in bc576fbaf82deded606e69a00efe9752136bf91d (fixed)

Vendor states this is fixed in bfd1d223d80cb29a210caa1bd5e21f0816d58f02 (fixed)

Vendor states this is fixed in e4d2102018542e3ae5e297bc6e229303abff8a0f (fixed)

Vendor states this is fixed in 5.10.229 (unaffected)

Affected range stops below 5.11, so it looks safe — our inference, not a vendor statement

Vendor states this is fixed in 5.15.171 (unaffected)

Affected range stops below 5.16, so it looks safe — our inference, not a vendor statement

Vendor states this is fixed in 6.1.116 (unaffected)

Vendor states this is fixed in 6.11.5 (unaffected)