| Message ID | 20241205170528.81000-1-hao.ge@linux.dev (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v3] mm/alloc_tag: fix vm_module_tags_populate's KASAN poisoning logic | expand |
On Thu, Dec 5, 2024 at 9:05 AM Hao Ge <hao.ge@linux.dev> wrote: > > From: Hao Ge <gehao@kylinos.cn> > > 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. > > 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@kylinos.cn> Acked-by: Suren Baghdasaryan <surenb@google.com> > --- > v3: Based on Suren's suggestion, I modified the code,Thank you for Suren. > I realized that the 'poisoned' is actually not needed, so I removed it > Due to these changes, update the commit message. > > 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 | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/lib/alloc_tag.c b/lib/alloc_tag.c > index 4ee6caa6d2da..f942408b53ef 100644 > --- a/lib/alloc_tag.c > +++ b/lib/alloc_tag.c > @@ -424,6 +424,15 @@ static int vm_module_tags_populate(void) > 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, > + new_end - module_tags.start_addr, > + KASAN_VMALLOC_PROT_NORMAL); > + > return 0; > } > > -- > 2.25.1 >
diff --git a/lib/alloc_tag.c b/lib/alloc_tag.c index 4ee6caa6d2da..f942408b53ef 100644 --- a/lib/alloc_tag.c +++ b/lib/alloc_tag.c @@ -424,6 +424,15 @@ static int vm_module_tags_populate(void) 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, + new_end - module_tags.start_addr, + KASAN_VMALLOC_PROT_NORMAL); + return 0; }