CVE Vulnerabilities

CVE-2024-41003

Published: Jul 12, 2024 | Modified: Jul 12, 2024
CVSS 3.x
N/A
Source:
NVD
CVSS 2.x
RedHat/V2
RedHat/V3
4.4 LOW
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
Ubuntu
MEDIUM

In the Linux kernel, the following vulnerability has been resolved:

bpf: Fix reg_set_min_max corruption of fake_reg

Juan reported that after doing some changes to buzzer [0] and implementing a new fuzzing strategy guided by coverage, they noticed the following in one of the probes:

[…] 13: (79) r6 = *(u64 *)(r0 +0) ; R0=map_value(ks=4,vs=8) R6_w=scalar() 14: (b7) r0 = 0 ; R0_w=0 15: (b4) w0 = -1 ; R0_w=0xffffffff 16: (74) w0 »= 1 ; R0_w=0x7fffffff 17: (5c) w6 &= w0 ; R0_w=0x7fffffff R6_w=scalar(smin=smin32=0,smax=umax=umax32=0x7fffffff,var_off=(0x0; 0x7fffffff)) 18: (44) w6 |= 2 ; R6_w=scalar(smin=umin=smin32=umin32=2,smax=umax=umax32=0x7fffffff,var_off=(0x2; 0x7ffffffd)) 19: (56) if w6 != 0x7ffffffd goto pc+1 REG INVARIANTS VIOLATION (true_reg2): range bounds violation u64=[0x7fffffff, 0x7ffffffd] s64=[0x7fffffff, 0x7ffffffd] u32=[0x7fffffff, 0x7ffffffd] s32=[0x7fffffff, 0x7ffffffd] var_off=(0x7fffffff, 0x0) REG INVARIANTS VIOLATION (false_reg1): range bounds violation u64=[0x7fffffff, 0x7ffffffd] s64=[0x7fffffff, 0x7ffffffd] u32=[0x7fffffff, 0x7ffffffd] s32=[0x7fffffff, 0x7ffffffd] var_off=(0x7fffffff, 0x0) REG INVARIANTS VIOLATION (false_reg2): const tnum out of sync with range bounds u64=[0x0, 0xffffffffffffffff] s64=[0x8000000000000000, 0x7fffffffffffffff] u32=[0x0, 0xffffffff] s32=[0x80000000, 0x7fffffff] var_off=(0x7fffffff, 0x0) 19: R6_w=0x7fffffff 20: (95) exit

from 19 to 21: R0=0x7fffffff R6=scalar(smin=umin=smin32=umin32=2,smax=umax=smax32=umax32=0x7ffffffe,var_off=(0x2; 0x7ffffffd)) R7=map_ptr(ks=4,vs=8) R9=ctx() R10=fp0 fp-24=map_ptr(ks=4,vs=8) fp-40=mmmmmmmm 21: R0=0x7fffffff R6=scalar(smin=umin=smin32=umin32=2,smax=umax=smax32=umax32=0x7ffffffe,var_off=(0x2; 0x7ffffffd)) R7=map_ptr(ks=4,vs=8) R9=ctx() R10=fp0 fp-24=map_ptr(ks=4,vs=8) fp-40=mmmmmmmm 21: (14) w6 -= 2147483632 ; R6_w=scalar(smin=umin=umin32=2,smax=umax=0xffffffff,smin32=0x80000012,smax32=14,var_off=(0x2; 0xfffffffd)) 22: (76) if w6 s>= 0xe goto pc+1 ; R6_w=scalar(smin=umin=umin32=2,smax=umax=0xffffffff,smin32=0x80000012,smax32=13,var_off=(0x2; 0xfffffffd)) 23: (95) exit

from 22 to 24: R0=0x7fffffff R6_w=14 R7=map_ptr(ks=4,vs=8) R9=ctx() R10=fp0 fp-24=map_ptr(ks=4,vs=8) fp-40=mmmmmmmm 24: R0=0x7fffffff R6_w=14 R7=map_ptr(ks=4,vs=8) R9=ctx() R10=fp0 fp-24=map_ptr(ks=4,vs=8) fp-40=mmmmmmmm 24: (14) w6 -= 14 ; R6_w=0 […]

What can be seen here is a register invariant violation on line 19. After the binary-or in line 18, the verifier knows that bit 2 is set but knows nothing about the rest of the content which was loaded from a map value, meaning, range is [2,0x7fffffff] with var_off=(0x2; 0x7ffffffd). When in line 19 the verifier analyzes the branch, it splits the register states in reg_set_min_max() into the registers of the true branch (true_reg1, true_reg2) and the registers of the false branch (false_reg1, false_reg2).

Since the test is w6 != 0x7ffffffd, the src_reg is a known constant. Internally, the verifier creates a fake register initialized as scalar to the value of 0x7ffffffd, and then passes it onto reg_set_min_max(). Now, for line 19, it is mathematically impossible to take the false branch of this program, yet the verifier analyzes it. It is impossible because the second bit of r6 will be set due to the prior or operation and the constant in the condition has that bit unset (hex(fd) == binary(1111 1101).

When the verifier first analyzes the false / fall-through branch, it will compute an intersection between the var_off of r6 and of the constant. This is because the verifier creates a fake register initialized to the value of the constant. The intersection result later refines both registers in regs_refine_cond_op():

[…] t = tnum_intersect(tnum_subreg(reg1->var_off), tnum_subreg(reg2->var_off)); reg1->var_o —truncated—

Affected Software

Name Vendor Start Version End Version
Linux Ubuntu noble *
Linux Ubuntu upstream *
Linux-allwinner-5.19 Ubuntu jammy *
Linux-allwinner-5.19 Ubuntu upstream *
Linux-aws Ubuntu noble *
Linux-aws Ubuntu upstream *
Linux-aws-5.0 Ubuntu bionic *
Linux-aws-5.0 Ubuntu esm-infra/bionic *
Linux-aws-5.0 Ubuntu upstream *
Linux-aws-5.11 Ubuntu focal *
Linux-aws-5.11 Ubuntu upstream *
Linux-aws-5.13 Ubuntu focal *
Linux-aws-5.13 Ubuntu upstream *
Linux-aws-5.15 Ubuntu upstream *
Linux-aws-5.19 Ubuntu jammy *
Linux-aws-5.19 Ubuntu upstream *
Linux-aws-5.3 Ubuntu bionic *
Linux-aws-5.3 Ubuntu esm-infra/bionic *
Linux-aws-5.3 Ubuntu upstream *
Linux-aws-5.4 Ubuntu upstream *
Linux-aws-5.8 Ubuntu focal *
Linux-aws-5.8 Ubuntu upstream *
Linux-aws-6.2 Ubuntu jammy *
Linux-aws-6.2 Ubuntu upstream *
Linux-aws-6.5 Ubuntu upstream *
Linux-aws-6.8 Ubuntu jammy *
Linux-aws-6.8 Ubuntu upstream *
Linux-aws-fips Ubuntu trusty *
Linux-aws-fips Ubuntu upstream *
Linux-aws-fips Ubuntu xenial *
Linux-aws-hwe Ubuntu upstream *
Linux-azure Ubuntu bionic *
Linux-azure Ubuntu esm-infra/bionic *
Linux-azure Ubuntu noble *
Linux-azure Ubuntu upstream *
Linux-azure-4.15 Ubuntu upstream *
Linux-azure-5.11 Ubuntu focal *
Linux-azure-5.11 Ubuntu upstream *
Linux-azure-5.13 Ubuntu focal *
Linux-azure-5.13 Ubuntu upstream *
Linux-azure-5.15 Ubuntu upstream *
Linux-azure-5.19 Ubuntu jammy *
Linux-azure-5.19 Ubuntu upstream *
Linux-azure-5.3 Ubuntu bionic *
Linux-azure-5.3 Ubuntu esm-infra/bionic *
Linux-azure-5.3 Ubuntu upstream *
Linux-azure-5.4 Ubuntu upstream *
Linux-azure-5.8 Ubuntu focal *
Linux-azure-5.8 Ubuntu upstream *
Linux-azure-6.2 Ubuntu jammy *
Linux-azure-6.2 Ubuntu upstream *
Linux-azure-6.5 Ubuntu upstream *
Linux-azure-6.8 Ubuntu jammy *
Linux-azure-6.8 Ubuntu upstream *
Linux-azure-edge Ubuntu bionic *
Linux-azure-edge Ubuntu esm-infra/bionic *
Linux-azure-edge Ubuntu upstream *
Linux-azure-fde Ubuntu focal *
Linux-azure-fde Ubuntu upstream *
Linux-azure-fde-5.15 Ubuntu upstream *
Linux-azure-fde-5.19 Ubuntu jammy *
Linux-azure-fde-5.19 Ubuntu upstream *
Linux-azure-fde-6.2 Ubuntu jammy *
Linux-azure-fde-6.2 Ubuntu upstream *
Linux-azure-fips Ubuntu trusty *
Linux-azure-fips Ubuntu upstream *
Linux-azure-fips Ubuntu xenial *
Linux-bluefield Ubuntu upstream *
Linux-fips Ubuntu upstream *
Linux-gcp Ubuntu bionic *
Linux-gcp Ubuntu esm-infra/bionic *
Linux-gcp Ubuntu noble *
Linux-gcp Ubuntu upstream *
Linux-gcp-4.15 Ubuntu upstream *
Linux-gcp-5.11 Ubuntu focal *
Linux-gcp-5.11 Ubuntu upstream *
Linux-gcp-5.13 Ubuntu focal *
Linux-gcp-5.13 Ubuntu upstream *
Linux-gcp-5.15 Ubuntu upstream *
Linux-gcp-5.19 Ubuntu jammy *
Linux-gcp-5.19 Ubuntu upstream *
Linux-gcp-5.3 Ubuntu bionic *
Linux-gcp-5.3 Ubuntu esm-infra/bionic *
Linux-gcp-5.3 Ubuntu upstream *
Linux-gcp-5.4 Ubuntu upstream *
Linux-gcp-5.8 Ubuntu focal *
Linux-gcp-5.8 Ubuntu upstream *
Linux-gcp-6.2 Ubuntu jammy *
Linux-gcp-6.2 Ubuntu upstream *
Linux-gcp-6.5 Ubuntu upstream *
Linux-gcp-6.8 Ubuntu jammy *
Linux-gcp-6.8 Ubuntu upstream *
Linux-gcp-fips Ubuntu trusty *
Linux-gcp-fips Ubuntu upstream *
Linux-gcp-fips Ubuntu xenial *
Linux-gke Ubuntu focal *
Linux-gke Ubuntu noble *
Linux-gke Ubuntu upstream *
Linux-gke Ubuntu xenial *
Linux-gke-4.15 Ubuntu bionic *
Linux-gke-4.15 Ubuntu esm-infra/bionic *
Linux-gke-4.15 Ubuntu upstream *
Linux-gke-5.15 Ubuntu focal *
Linux-gke-5.15 Ubuntu upstream *
Linux-gke-5.4 Ubuntu bionic *
Linux-gke-5.4 Ubuntu esm-infra/bionic *
Linux-gke-5.4 Ubuntu upstream *
Linux-gkeop Ubuntu upstream *
Linux-gkeop-5.15 Ubuntu upstream *
Linux-gkeop-5.4 Ubuntu bionic *
Linux-gkeop-5.4 Ubuntu esm-infra/bionic *
Linux-gkeop-5.4 Ubuntu upstream *
Linux-hwe Ubuntu bionic *
Linux-hwe Ubuntu esm-infra/bionic *
Linux-hwe Ubuntu upstream *
Linux-hwe-5.11 Ubuntu focal *
Linux-hwe-5.11 Ubuntu upstream *
Linux-hwe-5.13 Ubuntu focal *
Linux-hwe-5.13 Ubuntu upstream *
Linux-hwe-5.15 Ubuntu upstream *
Linux-hwe-5.19 Ubuntu jammy *
Linux-hwe-5.19 Ubuntu upstream *
Linux-hwe-5.4 Ubuntu upstream *
Linux-hwe-5.8 Ubuntu focal *
Linux-hwe-5.8 Ubuntu upstream *
Linux-hwe-6.2 Ubuntu jammy *
Linux-hwe-6.2 Ubuntu upstream *
Linux-hwe-6.5 Ubuntu jammy *
Linux-hwe-6.5 Ubuntu upstream *
Linux-hwe-6.8 Ubuntu jammy *
Linux-hwe-6.8 Ubuntu upstream *
Linux-hwe-edge Ubuntu esm-infra/bionic *
Linux-hwe-edge Ubuntu esm-infra/xenial *
Linux-hwe-edge Ubuntu upstream *
Linux-hwe-edge Ubuntu xenial *
Linux-ibm Ubuntu noble *
Linux-ibm Ubuntu upstream *
Linux-ibm-5.15 Ubuntu upstream *
Linux-ibm-5.4 Ubuntu upstream *
Linux-intel Ubuntu upstream *
Linux-intel-5.13 Ubuntu focal *
Linux-intel-5.13 Ubuntu upstream *
Linux-intel-iot-realtime Ubuntu upstream *
Linux-intel-iotg Ubuntu upstream *
Linux-intel-iotg-5.15 Ubuntu upstream *
Linux-iot Ubuntu upstream *
Linux-kvm Ubuntu upstream *
Linux-laptop Ubuntu upstream *
Linux-lowlatency Ubuntu noble *
Linux-lowlatency Ubuntu upstream *
Linux-lowlatency-hwe-5.15 Ubuntu upstream *
Linux-lowlatency-hwe-5.19 Ubuntu jammy *
Linux-lowlatency-hwe-5.19 Ubuntu upstream *
Linux-lowlatency-hwe-6.2 Ubuntu jammy *
Linux-lowlatency-hwe-6.2 Ubuntu upstream *
Linux-lowlatency-hwe-6.5 Ubuntu jammy *
Linux-lowlatency-hwe-6.5 Ubuntu upstream *
Linux-lowlatency-hwe-6.8 Ubuntu jammy *
Linux-lowlatency-hwe-6.8 Ubuntu upstream *
Linux-lts-xenial Ubuntu upstream *
Linux-nvidia Ubuntu noble *
Linux-nvidia Ubuntu upstream *
Linux-nvidia-6.2 Ubuntu jammy *
Linux-nvidia-6.2 Ubuntu upstream *
Linux-nvidia-6.5 Ubuntu upstream *
Linux-nvidia-6.8 Ubuntu jammy *
Linux-nvidia-6.8 Ubuntu upstream *
Linux-nvidia-lowlatency Ubuntu noble *
Linux-nvidia-lowlatency Ubuntu upstream *
Linux-oem Ubuntu bionic *
Linux-oem Ubuntu esm-infra/bionic *
Linux-oem Ubuntu upstream *
Linux-oem Ubuntu xenial *
Linux-oem-5.10 Ubuntu focal *
Linux-oem-5.10 Ubuntu upstream *
Linux-oem-5.13 Ubuntu focal *
Linux-oem-5.13 Ubuntu upstream *
Linux-oem-5.14 Ubuntu focal *
Linux-oem-5.14 Ubuntu upstream *
Linux-oem-5.17 Ubuntu jammy *
Linux-oem-5.17 Ubuntu upstream *
Linux-oem-5.6 Ubuntu focal *
Linux-oem-5.6 Ubuntu upstream *
Linux-oem-6.0 Ubuntu jammy *
Linux-oem-6.0 Ubuntu upstream *
Linux-oem-6.1 Ubuntu jammy *
Linux-oem-6.1 Ubuntu upstream *
Linux-oem-6.11 Ubuntu upstream *
Linux-oem-6.5 Ubuntu upstream *
Linux-oem-6.8 Ubuntu noble *
Linux-oem-6.8 Ubuntu upstream *
Linux-oracle Ubuntu noble *
Linux-oracle Ubuntu upstream *
Linux-oracle-5.0 Ubuntu bionic *
Linux-oracle-5.0 Ubuntu esm-infra/bionic *
Linux-oracle-5.0 Ubuntu upstream *
Linux-oracle-5.11 Ubuntu focal *
Linux-oracle-5.11 Ubuntu upstream *
Linux-oracle-5.13 Ubuntu focal *
Linux-oracle-5.13 Ubuntu upstream *
Linux-oracle-5.15 Ubuntu upstream *
Linux-oracle-5.3 Ubuntu bionic *
Linux-oracle-5.3 Ubuntu esm-infra/bionic *
Linux-oracle-5.3 Ubuntu upstream *
Linux-oracle-5.4 Ubuntu upstream *
Linux-oracle-5.8 Ubuntu focal *
Linux-oracle-5.8 Ubuntu upstream *
Linux-oracle-6.5 Ubuntu upstream *
Linux-oracle-6.8 Ubuntu jammy *
Linux-oracle-6.8 Ubuntu upstream *
Linux-raspi Ubuntu noble *
Linux-raspi Ubuntu upstream *
Linux-raspi-5.4 Ubuntu upstream *
Linux-raspi-realtime Ubuntu realtime/noble *
Linux-raspi-realtime Ubuntu upstream *
Linux-raspi2 Ubuntu bionic *
Linux-raspi2 Ubuntu focal *
Linux-raspi2 Ubuntu upstream *
Linux-raspi2 Ubuntu xenial *
Linux-realtime Ubuntu jammy *
Linux-realtime Ubuntu realtime/noble *
Linux-realtime Ubuntu upstream *
Linux-riscv Ubuntu focal *
Linux-riscv Ubuntu jammy *
Linux-riscv Ubuntu noble *
Linux-riscv Ubuntu upstream *
Linux-riscv-5.11 Ubuntu focal *
Linux-riscv-5.11 Ubuntu upstream *
Linux-riscv-5.15 Ubuntu upstream *
Linux-riscv-5.19 Ubuntu jammy *
Linux-riscv-5.19 Ubuntu upstream *
Linux-riscv-5.8 Ubuntu focal *
Linux-riscv-5.8 Ubuntu upstream *
Linux-riscv-6.5 Ubuntu upstream *
Linux-riscv-6.8 Ubuntu jammy *
Linux-riscv-6.8 Ubuntu upstream *
Linux-starfive Ubuntu upstream *
Linux-starfive-5.19 Ubuntu jammy *
Linux-starfive-5.19 Ubuntu upstream *
Linux-starfive-6.2 Ubuntu jammy *
Linux-starfive-6.2 Ubuntu upstream *
Linux-starfive-6.5 Ubuntu upstream *
Linux-xilinx-zynqmp Ubuntu upstream *

References