Commit be31340a authored by Mathieu Desnoyers's avatar Mathieu Desnoyers Committed by Andrew Morton
Browse files

mm: take into account mm_cid size for mm_struct static definitions 

Both init_mm and efi_mm static definitions need to make room for the 2
mm_cid cpumasks.

This fixes possible out-of-bounds accesses to init_mm and efi_mm.

Add a space between # and define for the mm_alloc_cid() definition to make
it consistent with the coding style used in the rest of this header file.

Link: https://lkml.kernel.org/r/20251224173358.647691-4-mathieu.desnoyers@efficios.com


Fixes: af7f588d ("sched: Introduce per-memory-map concurrency ID")
Signed-off-by: default avatarMathieu Desnoyers <mathieu.desnoyers@efficios.com>
Reviewed-by: default avatarThomas Gleixner <tglx@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Aboorva Devarajan <aboorvad@linux.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Christan König <christian.koenig@amd.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: "Liam R . Howlett" <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Martin Liu <liumartin@google.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: SeongJae Park <sj@kernel.org>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 6ac433f8

include/linux/mm_types.h

+5 −2
Original line number Diff line number Diff line
@@ -1368,7 +1368,7 @@ extern struct mm_struct init_mm; 


#define MM_STRUCT_FLEXIBLE_ARRAY_INIT				\

{								\

	[0 ... sizeof(cpumask_t)-1] = 0				\

	[0 ... sizeof(cpumask_t) + MM_CID_STATIC_SIZE - 1] = 0	\

}



/* Pointer magic because the dynamic array size confuses some compilers. */
@@ -1514,6 +1514,8 @@ static inline unsigned int mm_cid_size(void) 
	return cpumask_size() + bitmap_size(num_possible_cpus());

}



/* Use 2 * NR_CPUS as worse case for static allocation. */

# define MM_CID_STATIC_SIZE	(2 * sizeof(cpumask_t))

#else /* CONFIG_SCHED_MM_CID */

static inline void mm_init_cid(struct mm_struct *mm, struct task_struct *p) { }

static inline int mm_alloc_cid(struct mm_struct *mm, struct task_struct *p) { return 0; }
@@ -1522,6 +1524,7 @@ static inline unsigned int mm_cid_size(void) 
{

	return 0;

}

# define MM_CID_STATIC_SIZE	0

#endif /* CONFIG_SCHED_MM_CID */



struct mmu_gather;