[ Upstream commit afd07389d3f4933c7f7817a92fb5e053d59a3182 ] 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/[email protected] Signed-off-by: Uladzislau Rezki (Sony) <[email protected]> Reviewed-by: Andrew Morton <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Joel Fernandes <[email protected]> Cc: Matthew Wilcox <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Oleksiy Avramchenko <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: Tejun Heo <[email protected]> Cc: Thomas Garnier <[email protected]> Cc: Thomas Gleixner <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> Signed-off-by: Sasha Levin <[email protected]> --- mm/vmalloc.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 400e580725da..7c556b59f0ec 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -446,7 +446,11 @@ 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; -- 2.19.1
