From: Hao Ge <gehao@xxxxxxxxxx>
After merge commit 233e89322cbe ("alloc_tag:
fix module allocation tags populated area calculation"),
We still encountered a KASAN bug.
This is because we have only actually performed
page allocation and address mapping here.
we need to unpoisoned portions of underlying memory.
Because we have a change in the size here,we need to
re-annotate poisoned and unpoisoned portions of underlying memory
according to the new size.
Here is the log for KASAN:
[ 5.041171][ T1] ==================================================================
[ 5.042047][ T1] BUG: KASAN: vmalloc-out-of-bounds in move_module+0x2c0/0x708
[ 5.042723][ T1] Write of size 240 at addr ffff80007e510000 by task systemd/1
[ 5.043412][ T1]
[ 5.043523][ T72] input: QEMU QEMU USB Tablet as /devices/pci0000:00/0000:00:01.1/0000:02:001
[ 5.043614][ T1] CPU: 0 UID: 0 PID: 1 Comm: systemd Not tainted 6.13.0-rc1+ #28
[ 5.045560][ T1] Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015
[ 5.046328][ T1] Call trace:
[ 5.046670][ T1] show_stack+0x20/0x38 (C)
[ 5.047127][ T1] dump_stack_lvl+0x80/0xf8
[ 5.047533][ T1] print_address_description.constprop.0+0x58/0x358
[ 5.048092][ T72] hid-generic 0003:0627:0001.0001: input,hidraw0: USB HID v0.01 Mouse [QEMU 0
[ 5.048126][ T1] print_report+0xb0/0x280
[ 5.049682][ T1] kasan_report+0xb8/0x108
[ 5.050170][ T1] kasan_check_range+0xe8/0x190
[ 5.050685][ T1] memcpy+0x58/0xa0
[ 5.051135][ T1] move_module+0x2c0/0x708
[ 5.051586][ T1] layout_and_allocate.constprop.0+0x308/0x5b8
[ 5.052219][ T1] load_module+0x134/0x16c8
[ 5.052671][ T1] init_module_from_file+0xdc/0x138
[ 5.053193][ T1] idempotent_init_module+0x344/0x600
[ 5.053742][ T1] __arm64_sys_finit_module+0xbc/0x150
[ 5.054289][ T1] invoke_syscall+0xd4/0x258
[ 5.054749][ T1] el0_svc_common.constprop.0+0xb4/0x240
[ 5.055319][ T1] do_el0_svc+0x48/0x68
[ 5.055743][ T1] el0_svc+0x40/0xe0
[ 5.056142][ T1] el0t_64_sync_handler+0x10c/0x138
[ 5.056658][ T1] el0t_64_sync+0x1ac/0x1b0
Fixes: 233e89322cbe ("alloc_tag: fix module allocation tags populated area calculation")
Signed-off-by: Hao Ge <gehao@xxxxxxxxxx>
---
v2: Add comments to kasan_unpoison_vmalloc like other places.
commit 233e89322cbe ("alloc_tag: fix module allocation
tags populated area calculation") is currently in the
mm-hotfixes-unstable branch, so this patch is
developed based on the mm-hotfixes-unstable branch.
---
lib/alloc_tag.c | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/lib/alloc_tag.c b/lib/alloc_tag.c
index 4ee6caa6d2da..f885b3f3af0e 100644
--- a/lib/alloc_tag.c
+++ b/lib/alloc_tag.c
@@ -421,7 +421,20 @@ static int vm_module_tags_populate(void)
__free_page(next_page[i]);
return -ENOMEM;
}
+
+ kasan_poison_vmalloc((void *)module_tags.start_addr,
+ vm_module_tags->nr_pages << PAGE_SHIFT);
+
vm_module_tags->nr_pages += nr;
+
+ /*
+ * Mark the pages as accessible, now that they are mapped.
+ * With hardware tag-based KASAN, marking is skipped for
+ * non-VM_ALLOC mappings, see __kasan_unpoison_vmalloc().
+ */
+ kasan_unpoison_vmalloc((void *)module_tags.start_addr,
+ vm_module_tags->nr_pages << PAGE_SHIFT,
+ KASAN_VMALLOC_PROT_NORMAL);
}
return 0;
--
2.25.1
