0.0
NA
CVE-2025-39735
Linux Kernel JFS Slab Out-of-Bounds Read Vulnerability
Description

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 hex_dump_to_buffer() to get closer to the end of the actual bounds of "ptr", eventually an out of bounds access is done in hex_dump_to_buffer() in the following for loop: for (j = 0; j < len; j++) { if (linebuflen < lx + 2) goto overflow2; ch = ptr[j]; ... } To fix this we should validate "EALIST_SIZE(ea_buf->xattr)" before it is utilised.

INFO

Published Date :

April 18, 2025, 7:15 a.m.

Last Modified :

April 21, 2025, 2:23 p.m.

Source :

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Remotely Exploitable :

No

Impact Score :

Exploitability Score :

Affected Products

The following products are affected by CVE-2025-39735 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Linux linux_kernel

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2025-39735 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2025-39735 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    Apr. 18, 2025

    Action Type Old Value New Value
    Added Description 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 hex_dump_to_buffer() to get closer to the end of the actual bounds of "ptr", eventually an out of bounds access is done in hex_dump_to_buffer() in the following for loop: for (j = 0; j < len; j++) { if (linebuflen < lx + 2) goto overflow2; ch = ptr[j]; ... } To fix this we should validate "EALIST_SIZE(ea_buf->xattr)" before it is utilised.
    Added Reference https://git.kernel.org/stable/c/0beddc2a3f9b9cf7d8887973041e36c2d0fa3652
    Added Reference https://git.kernel.org/stable/c/16d3d36436492aa248b2d8045e75585ebcc2f34d
    Added Reference https://git.kernel.org/stable/c/3d6fd5b9c6acbc005e53d0211c7381f566babec1
    Added Reference https://git.kernel.org/stable/c/46e2c031aa59ea65128991cbca474bd5c0c2ecdb
    Added Reference https://git.kernel.org/stable/c/50afcee7011155933d8d5e8832f52eeee018cfd3
    Added Reference https://git.kernel.org/stable/c/5263822558a8a7c0d0248d5679c2dcf4d5cda61f
    Added Reference https://git.kernel.org/stable/c/78c9cbde8880ec02d864c166bcb4fe989ce1d95f
    Added Reference https://git.kernel.org/stable/c/a8c31808925b11393a6601f534bb63bac5366bab
    Added Reference https://git.kernel.org/stable/c/fdf480da5837c23b146c4743c18de97202fcab37
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2025-39735 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2025-39735 weaknesses.

NONE - Vulnerability Scoring System
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Latest DB Update: Apr. 21, 2025 14:40