The patch titled
Subject: mm/vmalloc.c: fix kernel BUG at mm/vmalloc.c:512!
has been added to the -mm tree. Its filename is
mm-vmalloc-fix-kernel-bug-at-mm-vmallocc-512.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-vmalloc-fix-kernel-bug-at-mm-vmallocc-512.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-vmalloc-fix-kernel-bug-at-mm-vmallocc-512.patch
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------------------------------------------------------
From: "Uladzislau Rezki (Sony)" <urezki@xxxxxxxxx>
Subject: mm/vmalloc.c: fix kernel BUG at mm/vmalloc.c:512!
One of the vmalloc stress test case triggers the kernel BUG():
<snip>
[60.562151] ------------[ cut here ]------------
[60.562154] kernel BUG at mm/vmalloc.c:512!
[60.562206] invalid opcode: 0000 [#1] PREEMPT SMP PTI
[60.562247] CPU: 0 PID: 430 Comm: vmalloc_test/0 Not tainted 4.20.0+ #161
[60.562293] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014
[60.562351] RIP: 0010:alloc_vmap_area+0x36f/0x390
<snip>
it can happen due to big align request resulting in overflowing of
calculated address, i.e. it becomes 0 after ALIGN()'s fixup.
Fix it by checking if calculated address is within vstart/vend range.
Link: http://lkml.kernel.org/r/20190124115648.9433-2-urezki@xxxxxxxxx
Signed-off-by: Uladzislau Rezki (Sony) <urezki@xxxxxxxxx>
Reviewed-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Joel Fernandes <joelaf@xxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@xxxxxxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Tejun Heo <tj@xxxxxxxxxx>
Cc: Thomas Garnier <thgarnie@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/vmalloc.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
--- a/mm/vmalloc.c~mm-vmalloc-fix-kernel-bug-at-mm-vmallocc-512
+++ a/mm/vmalloc.c
@@ -498,7 +498,11 @@ nocache:
}
found:
- if (addr + size > vend)
+ /*
+ * Check also calculated address against the vstart,
+ * because it can be 0 because of big align request.
+ */
+ if (addr + size > vend || addr < vstart)
goto overflow;
va->va_start = addr;
_
Patches currently in -mm which might be from urezki@xxxxxxxxx are
vmalloc-export-__vmalloc_node_range-for-config_test_vmalloc_module.patch
vmalloc-add-test-driver-to-analyse-vmalloc-allocator.patch
vmalloc-add-test-driver-to-analyse-vmalloc-allocator-fix.patch
selftests-vm-add-script-helper-for-config_test_vmalloc_module.patch
mm-vmalloc-fix-kernel-bug-at-mm-vmallocc-512.patch
mm-add-priority-threshold-to-__purge_vmap_area_lazy.patch
