From 786d2d84416a9a1c1a47b71a68d679d886284be2 Mon Sep 17 00:00:00 2001 From: Andrii Kuchmenko Date: Mon, 18 May 2026 17:32:33 +0300 Subject: 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. Fixes: b1ae6dc41eaa ("module: add in-kernel support for decompressing") Cc: Dmitry Torokhov Cc: Luis Chamberlain Cc: stable@vger.kernel.org Signed-off-by: Andrii Kuchmenko Reviewed-by: Christophe Leroy (CS GROUP) [Sami: Corrected the analysis in the commit message.] Signed-off-by: Sami Tolvanen --- kernel/module/decompress.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'kernel') diff --git a/kernel/module/decompress.c b/kernel/module/decompress.c index 36f52a232a12..cce098671be9 100644 --- a/kernel/module/decompress.c +++ b/kernel/module/decompress.c @@ -307,6 +307,8 @@ int module_decompress(struct load_info *info, const void *buf, size_t size) */ n_pages = DIV_ROUND_UP(size, PAGE_SIZE) * 2; error = module_extend_max_pages(info, n_pages); + if (error) + return error; data_size = MODULE_DECOMPRESS_FN(info, buf, size); if (data_size < 0) { -- cgit v1.2.3