linux/mm
David Laight 8446a4deb6 slab: kmalloc_size_roundup() must not return 0 for non-zero size
The typical use of kmalloc_size_roundup() is:

	ptr = kmalloc(sz = kmalloc_size_roundup(size), ...);
	if (!ptr) return -ENOMEM.

This means it is vitally important that the returned value isn't less
than the argument even if the argument is insane.
In particular if kmalloc_slab() fails or the value is above
(MAX_ULONG - PAGE_SIZE) zero is returned and kmalloc() will return
its single zero-length buffer ZERO_SIZE_PTR.

Fix this by returning the input size if the size exceeds
KMALLOC_MAX_SIZE. kmalloc() will then return NULL as the size really is
too big.

kmalloc_slab() should not normally return NULL, unless called too early.
Again, returning zero is not the correct action as it can be in some
usage scenarios stored to a variable and only later cause kmalloc()
return ZERO_SIZE_PTR and subsequent crashes on access. Instead we can
simply stop checking the kmalloc_slab() result completely, as calling
kmalloc_size_roundup() too early would then result in an immediate crash
during boot and the developer noticing an issue in their code.

[vbabka@suse.cz: remove kmalloc_slab() result check, tweak comments and
 commit log]
Fixes: 05a940656e ("slab: Introduce kmalloc_size_roundup()")
Signed-off-by: David Laight <david.laight@aculab.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2023-09-20 14:50:22 +02:00
..
damon Merge mm-hotfixes-stable into mm-stable to pick up depended-upon changes. 2023-06-23 16:58:19 -07:00
kasan kasan, slub: fix HW_TAGS zeroing with slub_debug 2023-07-08 09:29:32 -07:00
kfence Randomized slab caches for kmalloc() 2023-07-18 10:07:47 +02:00
kmsan kasan,kmsan: remove __GFP_KSWAPD_RECLAIM usage from kasan/kmsan 2023-06-23 16:59:26 -07:00
backing-dev.c mm: backing-dev: make bdi_class a static const structure 2023-06-23 16:59:27 -07:00
balloon_compaction.c
bootmem_info.c
cma.c mm/page_owner/cma: show pfn in cma/page_owner with hex format 2023-06-19 16:19:32 -07:00
cma.h
cma_debug.c
cma_sysfs.c mm: cma: make kobj_type structure constant 2023-03-28 16:20:06 -07:00
compaction.c mm: compaction: convert to use a folio in isolate_migratepages_block() 2023-06-23 16:59:31 -07:00
debug.c mm: update validate_mm() to use vma iterator 2023-06-09 16:25:31 -07:00
debug_page_alloc.c mm: page_alloc: split out DEBUG_PAGEALLOC 2023-06-09 16:25:23 -07:00
debug_page_ref.c
debug_vm_pgtable.c mm/debug_vm_pgtable,page_table_check: warn pte map fails 2023-06-19 16:19:15 -07:00
dmapool.c dmapool: create/destroy cleanup 2023-06-09 16:25:17 -07:00
dmapool_test.c dmapool: add alloc/free performance test 2023-04-05 19:42:38 -07:00
early_ioremap.c mm/early_ioremap.c: improve the execution efficiency of early_ioremap_setup() 2023-06-09 16:25:56 -07:00
fadvise.c mm: remove unnecessary pagevec includes 2023-06-23 16:59:31 -07:00
fail_page_alloc.c mm: page_alloc: split out FAIL_PAGE_ALLOC 2023-06-09 16:25:23 -07:00
failslab.c
filemap.c - Yosry Ahmed brought back some cgroup v1 stats in OOM logs. 2023-06-28 10:28:11 -07:00
folio-compat.c - Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of 2023-04-27 19:42:02 -07:00
frontswap.c mm: zswap: support exclusive loads 2023-06-19 16:19:05 -07:00
gup.c gup: make the stack expansion warning a bit more targeted 2023-07-05 09:33:31 -07:00
gup_test.c Merge mm-hotfixes-stable into mm-stable to pick up depended-upon changes. 2023-06-23 16:58:19 -07:00
gup_test.h
highmem.c mm: ptep_get() conversion 2023-06-19 16:19:25 -07:00
hmm.c mm: ptep_get() conversion 2023-06-19 16:19:25 -07:00
huge_memory.c mm: remove references to pagevec 2023-06-23 16:59:30 -07:00
hugetlb.c mm/hugetlb.c: fix a bug within a BUG(): inconsistent pte comparison 2023-07-08 09:29:29 -07:00
hugetlb_cgroup.c mm/hugetlb: increase use of folios in alloc_huge_page() 2023-02-13 15:54:27 -08:00
hugetlb_vmemmap.c mm: ptep_get() conversion 2023-06-19 16:19:25 -07:00
hugetlb_vmemmap.h
hwpoison-inject.c
init-mm.c IOMMU Updates for Linux 6.4 2023-04-30 13:00:38 -07:00
internal.h - Yosry Ahmed brought back some cgroup v1 stats in OOM logs. 2023-06-28 10:28:11 -07:00
interval_tree.c
io-mapping.c
ioremap.c
Kconfig Randomized slab caches for kmalloc() 2023-07-18 10:07:47 +02:00
Kconfig.debug mm: page_table_check: Make it dependent on EXCLUSIVE_SYSTEM_RAM 2023-05-29 16:14:28 +01:00
khugepaged.c mm/khugepaged: fix regression in collapse_file() 2023-06-29 09:41:45 -07:00
kmemleak.c lib/stackdepot, mm: rename stack_depot_want_early_init 2023-02-16 20:43:49 -08:00
ksm.c mm: remove references to pagevec 2023-06-23 16:59:30 -07:00
list_lru.c
maccess.c mm: Fix copy_from_user_nofault(). 2023-04-12 17:36:23 -07:00
madvise.c mm: ptep_get() conversion 2023-06-19 16:19:25 -07:00
Makefile mm: page_alloc: split out DEBUG_PAGEALLOC 2023-06-09 16:25:23 -07:00
mapping_dirty_helpers.c mm: ptep_get() conversion 2023-06-19 16:19:25 -07:00
memblock.c memblock: small updates for 6.5-rc1 2023-06-29 23:21:20 -07:00
memcontrol.c mm/memcontrol: do not tweak node in mem_cgroup_init() 2023-06-23 16:59:26 -07:00
memfd.c memfd: check for non-NULL file_seals in memfd_create() syscall 2023-06-19 13:19:31 -07:00
memory-failure.c mm: ptep_get() conversion 2023-06-19 16:19:25 -07:00
memory-tiers.c memory tier: remove unneeded !IS_ENABLED(CONFIG_MIGRATION) check 2023-06-19 16:19:29 -07:00
memory.c mm: call arch_swap_restore() from do_swap_page() 2023-07-08 09:29:30 -07:00
memory_hotplug.c mm: remove unnecessary pagevec includes 2023-06-23 16:59:31 -07:00
mempolicy.c mm: ptep_get() conversion 2023-06-19 16:19:25 -07:00
mempool.c
memremap.c mm/memremap.c: fix outdated comment in devm_memremap_pages 2023-02-09 16:51:46 -08:00
memtest.c mm/memtest: add results of early memtest to /proc/meminfo 2023-04-05 19:42:55 -07:00
migrate.c mm: remove unnecessary pagevec includes 2023-06-23 16:59:31 -07:00
migrate_device.c mm: remove references to pagevec 2023-06-23 16:59:30 -07:00
mincore.c mm: ptep_get() conversion 2023-06-19 16:19:25 -07:00
mlock.c mm: ptep_get() conversion 2023-06-19 16:19:25 -07:00
mm_init.c - Yosry Ahmed brought back some cgroup v1 stats in OOM logs. 2023-06-28 10:28:11 -07:00
mm_slot.h
mmap.c mm: lock newly mapped VMA with corrected ordering 2023-07-08 16:44:11 -07:00
mmap_lock.c
mmu_gather.c mm: prefer xxx_page() alloc/free functions for order-0 pages 2023-03-28 16:20:16 -07:00
mmu_notifier.c mm/mmu_notifier: remove unused mmu_notifier_range_update_to_read_only export 2023-02-02 22:32:54 -08:00
mmzone.c
mprotect.c Merge mm-hotfixes-stable into mm-stable to pick up depended-upon changes. 2023-06-23 16:58:19 -07:00
mremap.c mm: Update do_vmi_align_munmap() return semantics 2023-07-01 08:10:56 -07:00
msync.c
nommu.c xtensa: fix lock_mm_and_find_vma in case VMA not found 2023-07-01 08:00:05 -07:00
oom_kill.c mm, oom: do not check 0 mask in out_of_memory() 2023-06-09 16:25:20 -07:00
page-writeback.c writeback: account the number of pages written back 2023-07-08 09:29:30 -07:00
page_alloc.c - Yosry Ahmed brought back some cgroup v1 stats in OOM logs. 2023-06-28 10:28:11 -07:00
page_counter.c
page_ext.c mm/page_ext: init page_ext early if there are no deferred struct pages 2023-02-02 22:33:22 -08:00
page_idle.c
page_io.c swap: use __bio_add_page to add page to bio 2023-05-31 09:50:02 -06:00
page_isolation.c mm: page_isolation: write proper kerneldoc 2023-06-19 16:18:59 -07:00
page_owner.c mm/page_owner/cma: show pfn in cma/page_owner with hex format 2023-06-19 16:19:32 -07:00
page_poison.c
page_reporting.c mm, treewide: redefine MAX_ORDER sanely 2023-04-05 19:42:46 -07:00
page_reporting.h
page_table_check.c - Yosry Ahmed brought back some cgroup v1 stats in OOM logs. 2023-06-28 10:28:11 -07:00
page_vma_mapped.c mm: ptep_get() conversion 2023-06-19 16:19:25 -07:00
pagewalk.c mm/pagewalk: walk_pte_range() allow for pte_offset_map() 2023-06-19 16:19:14 -07:00
percpu-internal.h percpu-internal/pcpu_chunk: re-layout pcpu_chunk structure to reduce false sharing 2023-06-19 16:19:29 -07:00
percpu-km.c
percpu-stats.c
percpu-vm.c
percpu.c mm: memcontrol: rename memcg_kmem_enabled() 2023-02-16 20:43:56 -08:00
pgalloc-track.h
pgtable-generic.c mm: ptep_get() conversion 2023-06-19 16:19:25 -07:00
process_vm_access.c mm/gup: remove unused vmas parameter from pin_user_pages_remote() 2023-06-09 16:25:25 -07:00
ptdump.c mm: ptdump should use ptep_get_lockless() 2023-06-19 16:19:24 -07:00
readahead.c mm: remove unnecessary pagevec includes 2023-06-23 16:59:31 -07:00
rmap.c mm: ptep_get() conversion 2023-06-19 16:19:25 -07:00
rodata_test.c
secretmem.c mm/mlock: rename mlock_future_check() to mlock_future_ok() 2023-06-09 16:25:38 -07:00
shmem.c - Yosry Ahmed brought back some cgroup v1 stats in OOM logs. 2023-06-28 10:28:11 -07:00
show_mem.c mm: page_alloc: collect mem statistic into show_mem.c 2023-06-09 16:25:22 -07:00
shrinker_debug.c Revert "mm: shrinkers: make count and scan in shrinker debugfs lockless" 2023-06-19 13:19:34 -07:00
shuffle.c
shuffle.h mm, treewide: redefine MAX_ORDER sanely 2023-04-05 19:42:46 -07:00
slab.c Randomized slab caches for kmalloc() 2023-07-18 10:07:47 +02:00
slab.h Randomized slab caches for kmalloc() 2023-07-18 10:07:47 +02:00
slab_common.c slab: kmalloc_size_roundup() must not return 0 for non-zero size 2023-09-20 14:50:22 +02:00
slub.c mm/slub: remove freelist_dereference() 2023-07-14 09:57:21 +02:00
sparse-vmemmap.c mm: ptep_get() conversion 2023-06-19 16:19:25 -07:00
sparse.c - Arnd Bergmann has fixed a bunch of -Wmissing-prototypes in 2023-06-28 10:59:38 -07:00
swap.c mm: remove references to pagevec 2023-06-23 16:59:30 -07:00
swap.h mm: remove the __swap_writepage return value 2023-02-02 22:33:33 -08:00
swap_cgroup.c
swap_slots.c
swap_state.c mm: remove unnecessary pagevec includes 2023-06-23 16:59:31 -07:00
swapfile.c - Yosry Ahmed brought back some cgroup v1 stats in OOM logs. 2023-06-28 10:28:11 -07:00
truncate.c mm: remove references to pagevec 2023-06-23 16:59:30 -07:00
usercopy.c mm: Fix copy_from_user_nofault(). 2023-04-12 17:36:23 -07:00
userfaultfd.c mm: ptep_get() conversion 2023-06-19 16:19:25 -07:00
util.c mm: uninline kstrdup() 2023-04-08 13:45:37 -07:00
vmalloc.c Merge mm-hotfixes-stable into mm-stable to pick up depended-upon changes. 2023-06-23 16:58:19 -07:00
vmpressure.c
vmscan.c mm/vmscan: fix root proactive reclaim unthrottling unbalanced node 2023-06-23 16:59:32 -07:00
vmstat.c - Yosry Ahmed brought back some cgroup v1 stats in OOM logs. 2023-06-28 10:28:11 -07:00
workingset.c Multi-gen LRU: fix workingset accounting 2023-06-09 16:25:46 -07:00
z3fold.c mm: zswap: remove shrink from zpool interface 2023-06-19 16:19:27 -07:00
zbud.c mm: zswap: remove shrink from zpool interface 2023-06-19 16:19:27 -07:00
zpool.c mm: zswap: remove shrink from zpool interface 2023-06-19 16:19:27 -07:00
zsmalloc.c mm: zswap: remove shrink from zpool interface 2023-06-19 16:19:27 -07:00
zswap.c mm: zswap: fix double invalidate with exclusive loads 2023-06-23 16:59:31 -07:00