[Devel] [PATCH vz10] modules: use kvmalloc for the section attribute pointer array too

[Konstantin Khorenko]

The patch switched the struct module_sect_attrs allocation in
add_sect_attrs() to kvzalloc() so a module with many ELF sections
does not need a high-order allocation.

The RHEL10.2 base carries upstream f47c0bebed44 ("module: sysfs:
Simplify section attribute allocation"), which split the bin_attribute
pointer array out of that struct into its own allocation:

	gattr = kcalloc(nloaded + 1, sizeof(*gattr), GFP_KERNEL);

For a module with many sections this is another nloaded-sized array
that can cross a page and require a high-order allocation - exactly
what the patch set out to avoid. Allocate it with kvcalloc() and free
it with kvfree() in free_sect_attrs().

Fixes: 8b230b0af770 ("modules: use kvmalloc when creating sysfs attributes for ELF sections")

Reported-by: Pavel Tikhomirov <ptikhomirov at virtuozzo.com>
https://virtuozzo.atlassian.net/browse/VSTOR-132310
Signed-off-by: Konstantin Khorenko <khorenko at virtuozzo.com>
---
 kernel/module/sysfs.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/module/sysfs.c b/kernel/module/sysfs.c
index a896022e6186..4d0286559123 100644
--- a/kernel/module/sysfs.c
+++ b/kernel/module/sysfs.c
@@ -59,7 +59,7 @@ static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
 
 	for (bin_attr = sect_attrs->grp.bin_attrs_new; *bin_attr; bin_attr++)
 		kfree((*bin_attr)->attr.name);
-	kfree(sect_attrs->grp.bin_attrs_new);
+	kvfree(sect_attrs->grp.bin_attrs_new);
 	kvfree(sect_attrs);
 }
 
@@ -79,7 +79,7 @@ static int add_sect_attrs(struct module *mod, const struct load_info *info)
 	if (!sect_attrs)
 		return -ENOMEM;
 
-	gattr = kcalloc(nloaded + 1, sizeof(*gattr), GFP_KERNEL);
+	gattr = kvcalloc(nloaded + 1, sizeof(*gattr), GFP_KERNEL);
 	if (!gattr) {
 		kvfree(sect_attrs);
 		return -ENOMEM;
-- 
2.47.1