In the Linux kernel, the following vulnerability has been resolved: module: decompress: check return value of module_extend_max_pages() mo

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

module: decompress: check return value of module_extend_max_pages()

module_extend_max_pages() calls kvrealloc() internally and returns
-ENOMEM on allocation failure. The return value is never checked.

If the initial allocation fails, info->pages remains NULL and
info->max_pages remains 0. Subsequent calls to module_get_next_page()
will attempt to dynamically grow the array by calling
module_extend_max_pages(info, 0) since info->used_pages is 0. This
results in kvrealloc(NULL, 0) returning ZERO_SIZE_PTR, which is treated
as a success, leading to a dereference of ZERO_SIZE_PTR and a kernel
oops.

Fix: add the missing error check after module_extend_max_pages() and
return immediately on failure. This matches the pattern used by every
other kvrealloc() caller in the module loading path.

[Sami: Corrected the analysis in the commit message.]