In the Linux kernel, the following vulnerability has been resolved:
module: Fix kernel panic when a symbol st_shndx is out of bounds
The module loader doesn't check for bounds of the ELF section index in
simplify_symbols():
for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
const char *name = info->strtab + sym[i].st_name;
switch (sym[i].st_shndx) {
case SHN_COMMON:
[...]
default:
/* Divert to percpu allocation if a percpu var. */
if (sym[i].st_shndx == info->index.pcpu)
secbase = (unsigned long)mod_percpu(mod);
else
/** HERE --> **/ secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
sym[i].st_value += secbase;
break;
}
}
A symbol with an out-of-bounds st_shndx value, for example 0xffff
(known as SHN_XINDEX or SHN_HIRESERVE), may cause a kernel panic:
BUG: unable to handle page fault for address: ...
RIP: 0010:simplify_symbols+0x2b2/0x480
...
Kernel panic - not syncing: Fatal exception
This can happen when module ELF is legitimately using SHN_XINDEX or
when it is corrupted.
Add a bounds check in simplify_symbols() to validate that st_shndx is
within the valid range before using it.
This issue was discovered due to a bug in llvm-objcopy, see relevant
discussion for details [1].
[1] https://lore.kernel.org/linux-modules/20251224005752.201911-1-ihor.solodrai@linux.dev/
References
Configurations
Configuration 1 (hide)
|
History
28 Apr 2026, 18:26
| Type | Values Removed | Values Added |
|---|---|---|
| References | () https://git.kernel.org/stable/c/082f15d2887329e0f43fd3727e69365f5bfe5d2c - Patch | |
| References | () https://git.kernel.org/stable/c/4bbdb0e48176fd281c2b9a211b110db6fd94e175 - Patch | |
| References | () https://git.kernel.org/stable/c/5d16f519b6eb1d071807e57efe0df2baa8d32ad6 - Patch | |
| References | () https://git.kernel.org/stable/c/6ba6957c640f58dc8ef046981a045da43e47ea23 - Patch | |
| References | () https://git.kernel.org/stable/c/ec2b22a58073f80739013588af448ff6e2ab906f - Patch | |
| References | () https://git.kernel.org/stable/c/ef75dc1401d8e797ee51559a0dd0336c225e1776 - Patch | |
| References | () https://git.kernel.org/stable/c/f9d69d5e7bde2295eb7488a56f094ac8f5383b92 - Patch | |
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 5.5 |
| CWE | CWE-787 | |
| First Time |
Linux
Linux linux Kernel |
|
| CPE | cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:2.6.12:rc2:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:2.6.12:-:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:2.6.12:rc5:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:2.6.12:rc4:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:2.6.12:rc3:*:*:*:*:*:* |
22 Apr 2026, 14:16
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-04-22 14:16
Updated : 2026-04-28 18:26
NVD link : CVE-2026-31521
Mitre link : CVE-2026-31521
CVE.ORG link : CVE-2026-31521
JSON object : View
Products Affected
linux
- linux_kernel
CWE
CWE-787
Out-of-bounds Write