cbcvebase.
CVE-2024-49861
published 2024-10-21

CVE-2024-49861: In the Linux kernel, the following vulnerability has been resolved: bpf: Fix helper writes to read-only maps Lonial found an issue that despite user- and…

PriorityP430high7.1CVSS 3.1
AVLACLPRLUINSUCNIHAH
EPSS
0.22%
13.2th percentile
In the Linux kernel, the following vulnerability has been resolved: bpf: Fix helper writes to read-only maps Lonial found an issue that despite user- and BPF-side frozen BPF map (like in case of .rodata), it was still possible to write into it from a BPF program side through specific helpers having ARG_PTR_TO_{LONG,INT} as arguments. In check_func_arg() when the argument is as mentioned, the meta->raw_mode is never set. Later, check_helper_mem_access(), under the case of PTR_TO_MAP_VALUE as register base type, it assumes BPF_READ for the subsequent call to check_map_access_type() and given the BPF map is read-only it succeeds. The helpers really need to be annotated as ARG_PTR_TO_{LONG,INT} | MEM_UNINIT when results are written into them as opposed to read out of them. The latter indicates that it's okay to pass a pointer to uninitialized memory as the memory is written to anyway. However, ARG_PTR_TO_{LONG,INT} is a special case of ARG_PTR_TO_FIXED_SIZE_MEM just with additional alignment requirement. So it is better to just get rid of the ARG_PTR_TO_{LONG,INT} special cases altogether and reuse the fixed size memory types. For this, add MEM_ALIGNED to additionally ensure alignment given these helpers write directly into the args via * = val. The .arg*_size has been initialized reflecting the actual sizeof(*). MEM_ALIGNED can only be used in combination with MEM_FIXED_SIZE annotated argument types, since in !MEM_FIXED_SIZE cases the verifier does not know the buffer size a priori and therefore cannot blindly write * = val.

Affected

24 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 6.1.123-1 (bookworm)linux 6.1.123-1 (bookworm)
debianlinux-6.1< linux 6.1.123-1 (bookworm)linux 6.1.123-1 (bookworm)
googlechrome_chrome
linuxlinux
linuxlinux>= 57c3bb725a3dd97d960d7e1cd0845d88de53217f < 988e55abcf7fdb8fc9a76a7cf3f4e939a4d4fb3a988e55abcf7fdb8fc9a76a7cf3f4e939a4d4fb3a
linuxlinux>= 57c3bb725a3dd97d960d7e1cd0845d88de53217f < a2c8dc7e21803257e762b0bf067fd13e9c995da0a2c8dc7e21803257e762b0bf067fd13e9c995da0
linuxlinux>= 57c3bb725a3dd97d960d7e1cd0845d88de53217f < 2ed98ee02d1e08afee88f54baec39ea78dc8a23c2ed98ee02d1e08afee88f54baec39ea78dc8a23c
linuxlinux>= 57c3bb725a3dd97d960d7e1cd0845d88de53217f < 1e75d25133158b525e0456876e9bcfd6b2993fd51e75d25133158b525e0456876e9bcfd6b2993fd5
linuxlinux>= 57c3bb725a3dd97d960d7e1cd0845d88de53217f < 32556ce93bc45c730829083cb60f95a2728ea48b32556ce93bc45c730829083cb60f95a2728ea48b
linuxlinux_kernel>= 0 < 6.1.123-16.1.123-1
linuxlinux_kernel>= 0 < 6.11.2-16.11.2-1
linuxlinux_kernel>= 0 < 6.11.2-16.11.2-1
linuxlinux_kernel>= 0 < 6.8.0-54.566.8.0-54.56
linuxlinux_kernel>= 0 < 6.11.0-18.186.11.0-18.18
linuxlinux_kernel>= 5.2 < 6.6.546.6.54
linuxlinux_kernel>= 6.11 < 6.11.26.11.2
linuxlinux_kernel>= 6.7 < 6.10.136.10.13
msrcazl3_kernel_6.6.51.1-5_on_azure_linux_3.0
msrcazl3_kernel_6.6.56.1-5_on_azure_linux_3.0
msrcazure_linux_3.0_arm
msrcazure_linux_3.0_x64
msrccbl2_kernel_5.15.186.1-1_on_cbl_mariner_2.0
msrccbl2_kernel_5.15.200.1-1_on_cbl_mariner_2.0
msrccbl2_kernel_5.15.202.1-1_on_cbl_mariner_2.0

CVSS provenance

nvdv3.17.1HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
osv8.8HIGH
vendor_ubuntu8.8HIGH
vendor_debian7.1HIGH
vendor_msrc7.1HIGH
vendor_redhat7.1HIGH
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