jfs: fix slab-out-of-bounds read in ea_get() (CVE-2025-39735)

Résumé

jfs: fix slab-out-of-bounds read in ea_get()

Description d'origine

La description telle que publiée par la source (souvent en anglais).

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

jfs: fix slab-out-of-bounds read in ea_get()

During the "size_check" label in ea_get(), the code checks if the extended
attribute list (xattr) size matches ea_size. If not, it logs
"ea_get: invalid extended attribute" and calls print_hex_dump().

Here, EALIST_SIZE(ea_buf->xattr) returns 4110417968, which exceeds
INT_MAX (2,147,483,647). Then ea_size is clamped:

int size = clamp_t(int, ea_size, 0, EALIST_SIZE(ea_buf->xattr));

Although clamp_t aims to bound ea_size between 0 and 4110417968, the upper
limit is treated as an int, causing an overflow above 2^31 - 1. This leads
"size" to wrap around and become negative (-184549328).

The "size" is then passed to print_hex_dump() (called "len" in
print_hex_dump()), it is passed as type size_t (an unsigned
type), this is then stored inside a variable called
"int remaining", which is then assigned to "int linelen" which
is then passed to hex_dump_to_buffer(). In print_hex_dump()
the for loop, iterates through 0 to len-1, where len is
18446744073525002176, calling hex_dump_to_buffer()
on each iteration:

for (i = 0; i < len; i += rowsize) {
	linelen = min(remaining, rowsize);
	remaining -= rowsize;

	hex_dump_to_buffer(ptr + i, linelen, rowsize, groupsize,
			   linebuf, sizeof(linebuf), ascii);

	...
}

The expected stopping condition (i < len) is effectively broken
since len is corrupted and very large. This eventually leads to
the "ptr+i" being passed to…

Source: OSV.dev (Open Source Vulnerabilities) NVD OSV

Paquets affectés

Linux Kernel

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.292"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.5.0"},{"fixed":"5.10.236"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.180"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.134"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.87"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.23"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.13.11"},{"fixed":"6.14.2"}]}]

État des correctifs par distribution

Paquets corrigés publiés par chaque distribution pour cette CVE

BellSoft Alpaquita BELL-CVE-2025-39735 linux-lts Corrigé dans: 6.1.134-r0
Debian DEBIAN-CVE-2025-39735 linux Corrigé dans: 5.10.237-1
Ubuntu UBUNTU-CVE-2025-39735 linux-hwe-edge

Résumé

Description d'origine

Paquets affectés

État des correctifs par distribution

Références