In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix KMSAN uninit-value in extent_info usage
KMSAN reported a use of uninitialized value in __is_extent_mergeable()
and __is_back_mergeable() via the read extent tree path.
The root cause is that get_read_extent_info() only initializes three
fields (fofs, blk, len) of struct extent_info, leaving the
remaining fields uninitialized. This leads to undefined behavior
when those fields are accessed later, especially during
extent merging.
Fix it by zero-initializing the extent_info struct before population.
[
{
"signature_version": "v1",
"deprecated": false,
"digest": {
"function_hash": "178643759224058819479060835699722349548",
"length": 1038.0
},
"source": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git@cc1615d5aba4f396cf412579928539a2b124c8a0",
"id": "CVE-2025-38579-30c9c7eb",
"signature_type": "Function",
"target": {
"function": "f2fs_init_read_extent_tree",
"file": "fs/f2fs/extent_cache.c"
}
},
{
"signature_version": "v1",
"deprecated": false,
"digest": {
"threshold": 0.9,
"line_hashes": [
"57809904543385259674042874993128232154",
"192874406106797115932895038712944849518",
"15487074288741944666858909643565863539",
"19488881582710685622947487285962714631"
]
},
"source": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git@cc1615d5aba4f396cf412579928539a2b124c8a0",
"id": "CVE-2025-38579-84d19a06",
"signature_type": "Line",
"target": {
"file": "fs/f2fs/extent_cache.c"
}
},
{
"signature_version": "v1",
"deprecated": false,
"digest": {
"function_hash": "62410681316457024214001723746931363790",
"length": 973.0
},
"source": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git@44a79437309e0ee2276ac17aaedc71253af253a8",
"id": "CVE-2025-38579-a8556b08",
"signature_type": "Function",
"target": {
"function": "f2fs_init_read_extent_tree",
"file": "fs/f2fs/extent_cache.c"
}
},
{
"signature_version": "v1",
"deprecated": false,
"digest": {
"threshold": 0.9,
"line_hashes": [
"57809904543385259674042874993128232154",
"192874406106797115932895038712944849518",
"15487074288741944666858909643565863539",
"19488881582710685622947487285962714631"
]
},
"source": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git@44a79437309e0ee2276ac17aaedc71253af253a8",
"id": "CVE-2025-38579-c47bafc9",
"signature_type": "Line",
"target": {
"file": "fs/f2fs/extent_cache.c"
}
}
]