If the kernel command line includes "debug_guardpage_minorder" without an
equals sign (i.e., no value is provided), the early parameter parser
passes a NULL buf pointer to the setup function.
kstrtouint() does not perform a NULL check on its input and calls directly
into kstrtoull() which dereferences s[0] unconditionally, leading to a
NULL pointer dereference and early boot crash.
Additionally, the error path's pr_err("%s", buf) would also crash with a
NULL format argument.
Link: https://lore.kernel.org/[email protected]
Fixes: c0a32fc5a2 ("mm: more intensive memory corruption debugging")
Signed-off-by: Ye Liu <[email protected]>
Acked-by: Zi Yan <[email protected]>
Reviewed-by: John Hubbard <[email protected]>
Reviewed-by: Andrew Morton <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
commit 23baf831a3 ("mm, treewide: redefine MAX_ORDER sanely") has
changed the definition of MAX_ORDER to be inclusive. This has caused
issues with code that was not yet upstream and depended on the previous
definition.
To draw attention to the altered meaning of the define, rename MAX_ORDER
to MAX_PAGE_ORDER.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Kirill A. Shutemov <[email protected]>
Cc: Linus Torvalds <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Ye Liu