In the Linux kernel, the following vulnerability has been resolved:
parisc: Fix random data corruption from exception handler
The current exception handler implementation, which assists when accessing
user space memory, may exhibit random data corruption if the compiler decides
to use a different register than the specified register %r29 (defined in
ASM_EXCEPTIONTABLE_REG) for the error code. If the compiler choose another
register, the fault handler will nevertheless store -EFAULT into %r29 and thus
trash whatever this register is used for.
Looking at the assembly I found that this happens sometimes in emulate_ldd().
To solve the issue, the easiest solution would be if it somehow is
possible to tell the fault handler which register is used to hold the error
code. Using %0 or %1 in the inline assembly is not posssible as it will show
up as e.g. %r29 (with the "%r" prefix), which the GNU assembler can not
convert to an integer.
This patch takes another, better and more flexible approach:
We extend the __ex_table (which is out of the execution path) by one 32-word.
In this word we tell the compiler to insert the assembler instruction
"or %r0,%r0,%reg", where %reg references the register which the compiler
choosed for the error return code.
In case of an access failure, the fault handler finds the __ex_table entry and
can examine the opcode. The used register is encoded in the lowest 5 bits, and
the fault handler can then store -EFAULT into this register.
Since we extend the __ex_table to 3 words we can't use the BUILDTIME_TABLE_SORT
config option any longer.
References
Configurations
Configuration 1 (hide)
|
History
17 Mar 2025, 15:36
Type | Values Removed | Values Added |
---|---|---|
CPE | cpe:2.3:o:linux:linux_kernel:6.8:rc2:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.8:rc1:*:*:*:*:*:* |
|
CWE | CWE-787 | |
First Time |
Linux linux Kernel
Linux |
|
CVSS |
v2 : v3 : |
v2 : unknown
v3 : 5.5 |
References | () https://git.kernel.org/stable/c/23027309b099ffc4efca5477009a11dccbdae592 - Patch | |
References | () https://git.kernel.org/stable/c/8b1d72395635af45410b66cc4c4ab37a12c4a831 - Patch | |
References | () https://git.kernel.org/stable/c/ce31d79aa1f13a2345791f84935281a2c194e003 - Patch | |
References | () https://git.kernel.org/stable/c/fa69a8063f8b27f3c7434a0d4f464a76a62f24d2 - Patch |
Information
Published : 2024-04-03 15:15
Updated : 2025-03-17 15:36
NVD link : CVE-2024-26706
Mitre link : CVE-2024-26706
CVE.ORG link : CVE-2024-26706
JSON object : View
Products Affected
linux
- linux_kernel
CWE
CWE-787
Out-of-bounds Write