linux/mm
Thadeu Lima de Souza Cascardo 3f0c44c8c2 codetag: avoid race at alloc_slab_obj_exts
When CONFIG_MEM_ALLOC_PROFILING_DEBUG is enabled, the following warning
may be noticed:

[   48.299584] ------------[ cut here ]------------
[   48.300092] alloc_tag was not set
[   48.300528] WARNING: CPU: 2 PID: 1361 at include/linux/alloc_tag.h:130 alloc_tagging_slab_free_hook+0x84/0xc7
[   48.301305] Modules linked in:
[   48.301553] CPU: 2 PID: 1361 Comm: systemd-udevd Not tainted 6.10.0-rc1-00003-gac8755535862 #176
[   48.302196] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
[   48.302752] RIP: 0010:alloc_tagging_slab_free_hook+0x84/0xc7
[   48.303169] Code: 8d 1c c4 48 85 db 74 4d 48 83 3b 00 75 1e 80 3d 65 02 86 04 00 75 15 48 c7 c7 11 48 1d 85 c6 05 55 02 86 04 01 e8 64 44 a5 ff <0f> 0b 48 8b 03 48 85 c0 74 21 48 83 f8 01 74 14 48 8b 50 20 48 f7
[   48.304411] RSP: 0018:ffff8880111b7d40 EFLAGS: 00010282
[   48.304916] RAX: 0000000000000000 RBX: ffff88800fcc9008 RCX: 0000000000000000
[   48.305455] RDX: 0000000080000000 RSI: ffff888014060000 RDI: ffffed1002236f97
[   48.305979] RBP: 0000000000001100 R08: fffffbfff0aa73a1 R09: 0000000000000000
[   48.306473] R10: ffffffff814515e5 R11: 0000000000000003 R12: ffff88800fcc9000
[   48.306943] R13: ffff88800b2e5cc0 R14: ffff8880111b7d90 R15: 0000000000000000
[   48.307529] FS:  00007faf5d1908c0(0000) GS:ffff88806cf00000(0000) knlGS:0000000000000000
[   48.308223] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   48.308710] CR2: 000058fb220c9118 CR3: 00000000110cc000 CR4: 0000000000750ef0
[   48.309274] PKRU: 55555554
[   48.309804] Call Trace:
[   48.310029]  <TASK>
[   48.310290]  ? show_regs+0x84/0x8d
[   48.310722]  ? alloc_tagging_slab_free_hook+0x84/0xc7
[   48.311298]  ? __warn+0x13b/0x2ff
[   48.311580]  ? alloc_tagging_slab_free_hook+0x84/0xc7
[   48.311987]  ? report_bug+0x2ce/0x3ab
[   48.312292]  ? handle_bug+0x8c/0x107
[   48.312563]  ? exc_invalid_op+0x34/0x6f
[   48.312842]  ? asm_exc_invalid_op+0x1a/0x20
[   48.313173]  ? this_cpu_in_panic+0x1c/0x72
[   48.313503]  ? alloc_tagging_slab_free_hook+0x84/0xc7
[   48.313880]  ? putname+0x143/0x14e
[   48.314152]  kmem_cache_free+0xe9/0x214
[   48.314454]  putname+0x143/0x14e
[   48.314712]  do_unlinkat+0x413/0x45e
[   48.315001]  ? __pfx_do_unlinkat+0x10/0x10
[   48.315388]  ? __check_object_size+0x4d7/0x525
[   48.315744]  ? __sanitizer_cov_trace_pc+0x20/0x4a
[   48.316167]  ? __sanitizer_cov_trace_pc+0x20/0x4a
[   48.316757]  ? getname_flags+0x4ed/0x500
[   48.317261]  __x64_sys_unlink+0x42/0x4a
[   48.317741]  do_syscall_64+0xe2/0x149
[   48.318171]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
[   48.318602] RIP: 0033:0x7faf5d8850ab
[   48.318891] Code: fd ff ff e8 27 dd 01 00 0f 1f 80 00 00 00 00 f3 0f 1e fa b8 5f 00 00 00 0f 05 c3 0f 1f 40 00 f3 0f 1e fa b8 57 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 05 c3 0f 1f 40 00 48 8b 15 41 2d 0e 00 f7 d8
[   48.320649] RSP: 002b:00007ffc44982b38 EFLAGS: 00000246 ORIG_RAX: 0000000000000057
[   48.321182] RAX: ffffffffffffffda RBX: 00005ba344a44680 RCX: 00007faf5d8850ab
[   48.321667] RDX: 0000000000000000 RSI: 00005ba344a44430 RDI: 00007ffc44982b40
[   48.322139] RBP: 00007ffc44982c00 R08: 0000000000000000 R09: 0000000000000007
[   48.322598] R10: 00005ba344a44430 R11: 0000000000000246 R12: 0000000000000000
[   48.323071] R13: 00007ffc44982b40 R14: 0000000000000000 R15: 0000000000000000
[   48.323596]  </TASK>

This is due to a race when two objects are allocated from the same slab,
which did not have an obj_exts allocated for.

In such a case, the two threads will notice the NULL obj_exts and after
one assigns slab->obj_exts, the second one will happily do the exchange if
it reads this new assigned value.

In order to avoid that, verify that the read obj_exts does not point to an
allocated obj_exts before doing the exchange.

Link: https://lkml.kernel.org/r/20240527183007.1595037-1-cascardo@igalia.com
Fixes: 09c46563ff ("codetag: debug: introduce OBJEXTS_ALLOC_FAIL to mark failed slab_ext allocations")
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@igalia.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Gustavo A. R. Silva <gustavoars@kernel.org>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Thadeu Lima de Souza Cascardo <cascardo@igalia.com>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-06-05 19:19:26 -07:00
..
damon mm/damon/core: fix return value from damos_wmark_metric_value 2024-05-11 15:41:36 -07:00
kasan fix missing vmalloc.h includes 2024-04-25 20:55:49 -07:00
kfence mm: introduce slabobj_ext to support slab object extensions 2024-04-25 20:55:51 -07:00
kmsan kmsan: do not wipe out origin when doing partial unpoisoning 2024-06-05 19:19:25 -07:00
backing-dev.c writeback: support retrieving per group debug writeback stats of bdi 2024-05-05 17:53:51 -07:00
balloon_compaction.c
bootmem_info.c bootmem: use kmemleak_free_part_phys in put_page_bootmem 2023-10-25 16:47:13 -07:00
cma.c mm/cma: drop incorrect alignment check in cma_init_reserved_mem 2024-04-25 20:56:42 -07:00
cma.h mm/cma: add sysfs file 'release_pages_success' 2024-02-22 10:24:57 -08:00
cma_debug.c
cma_sysfs.c mm/cma: add sysfs file 'release_pages_success' 2024-02-22 10:24:57 -08:00
compaction.c memory: remove the now superfluous sentinel element from ctl_table array 2024-04-25 20:56:32 -07:00
debug.c mm/debug: print only page mapcount (excluding folio entire mapcount) in __dump_folio() 2024-05-05 17:53:31 -07:00
debug_page_alloc.c mm: page_alloc: consolidate free page accounting 2024-04-25 20:56:04 -07:00
debug_page_ref.c
debug_vm_pgtable.c mm/debug_vm_pgtable: test pmd_leaf() behavior with pmd_mkinvalid() 2024-05-07 10:37:00 -07:00
dmapool.c mm/mempool/dmapool: remove CONFIG_DEBUG_SLAB ifdefs 2023-12-05 11:17:58 +01:00
dmapool_test.c
early_ioremap.c
execmem.c mm/execmem, arch: convert remaining overrides of module_alloc to execmem 2024-05-14 00:31:43 -07:00
fadvise.c mm: remove unnecessary pagevec includes 2023-06-23 16:59:31 -07:00
fail_page_alloc.c
failslab.c
filemap.c The usual shower of singleton fixes and minor series all over MM, 2024-05-19 09:21:03 -07:00
folio-compat.c mm: remove __set_page_dirty_nobuffers() 2024-04-25 20:56:25 -07:00
gup.c mm/gup: fix hugepd handling in hugetlb rework 2024-05-07 10:37:01 -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 x86/kexec: use pr_err() instead of kexec_dprintk() when an error occurs 2023-12-29 12:22:28 -08:00
hmm.c mm/treewide: replace pXd_huge() with pXd_leaf() 2024-04-25 20:55:46 -07:00
huge_memory.c mm: drop the 'anon_' prefix for swap-out mTHP counters 2024-06-05 19:19:23 -07:00
hugetlb.c mm/hugetlb: do not call vma_add_reservation upon ENOMEM 2024-06-05 19:19:26 -07:00
hugetlb_cgroup.c mm/hugetlb: assert hugetlb_lock in __hugetlb_cgroup_commit_charge 2024-05-05 17:53:41 -07:00
hugetlb_vmemmap.c memory: remove the now superfluous sentinel element from ctl_table array 2024-04-25 20:56:32 -07:00
hugetlb_vmemmap.h mm: hugetlb_vmemmap: fix reference to nonexistent file 2023-10-25 16:47:14 -07:00
hwpoison-inject.c mm/memory-failure: convert shake_page() to shake_folio() 2024-05-05 17:53:45 -07:00
init-mm.c mm: Deprecate pasid field 2023-12-12 10:11:32 +01:00
internal.h mseal: add mseal syscall 2024-05-23 19:40:26 -07:00
interval_tree.c
io-mapping.c
ioremap.c mm: ioremap: remove unneeded ioremap_allowed and iounmap_allowed 2023-08-18 10:12:36 -07:00
Kconfig The usual shower of singleton fixes and minor series all over MM, 2024-05-19 09:21:03 -07:00
Kconfig.debug mm/slub: unify all sl[au]b parameters with "slab_$param" 2024-01-22 10:31:08 +01:00
khugepaged.c mm: simplify thp_vma_allowable_order 2024-05-05 17:53:53 -07:00
kmemleak.c mm: lift gfp_kmemleak_mask() to gfp.h 2024-05-19 14:40:44 -07:00
ksm.c mm/ksm: fix ksm_zero_pages accounting 2024-06-05 19:19:26 -07:00
list_lru.c mm/zswap: stop lru list shrinking when encounter warm region 2024-02-22 10:24:54 -08:00
maccess.c
madvise.c mseal: add mseal syscall 2024-05-23 19:40:26 -07:00
Makefile mseal: add mseal syscall 2024-05-23 19:40:26 -07:00
mapping_dirty_helpers.c mm: fix clean_record_shared_mapping_range kernel-doc 2023-08-24 16:20:30 -07:00
memblock.c cxl fixes for 6.8-rc6 2024-02-24 15:53:40 -08:00
memcontrol.c memcg: remove the lockdep assert from __mod_objcg_mlstate() 2024-06-05 19:19:24 -07:00
memfd.c mm/memfd: refactor memfd_tag_pins() and memfd_wait_for_pins() 2024-03-04 17:01:21 -08:00
memory-failure.c mm/memory-failure: fix handling of dissolved but not taken off from buddy pages 2024-05-24 11:55:08 -07:00
memory-tiers.c memory tier: create CPUless memory tiers after obtaining HMAT info 2024-05-05 17:53:26 -07:00
memory.c mm: simplify and improve print_vma_addr() output 2024-05-22 14:37:23 -07:00
memory_hotplug.c mm/hugetlb: rename dissolve_free_huge_pages() to dissolve_free_hugetlb_folios() 2024-05-05 17:53:35 -07:00
mempolicy.c mm: add pmd_folio() 2024-04-25 20:56:19 -07:00
mempool.c mempool: hook up to memory allocation profiling 2024-04-25 20:55:56 -07:00
memremap.c mm: convert put_devmap_managed_page_refs() to put_devmap_managed_folio_refs() 2024-05-05 17:53:49 -07:00
memtest.c memtest: use {READ,WRITE}_ONCE in memory scanning 2024-03-13 12:12:21 -07:00
migrate.c mm: convert hugetlb_page_mapping_lock_write to folio 2024-05-05 17:53:46 -07:00
migrate_device.c The usual shower of singleton fixes and minor series all over MM, 2024-05-19 09:21:03 -07:00
mincore.c mm: enable page walking API to lock vmas during the walk 2023-08-21 13:07:20 -07:00
mlock.c mm: add pmd_folio() 2024-04-25 20:56:19 -07:00
mm_init.c The usual shower of singleton fixes and minor series all over MM, 2024-05-19 09:21:03 -07:00
mm_slot.h
mmap.c mseal: add mseal syscall 2024-05-23 19:40:26 -07:00
mmap_lock.c
mmu_gather.c mm/mmu_gather: improve cond_resched() handling with large folios and expensive page freeing 2024-02-22 15:27:17 -08:00
mmu_notifier.c mmu_notifier: remove the .change_pte() callback 2024-04-11 13:18:36 -04:00
mmzone.c zswap: shrink zswap pool based on memory pressure 2023-12-12 10:57:02 -08:00
mprotect.c mseal: add mseal syscall 2024-05-23 19:40:26 -07:00
mremap.c mseal: add mseal syscall 2024-05-23 19:40:26 -07:00
mseal.c mseal: add mseal syscall 2024-05-23 19:40:26 -07:00
msync.c
nommu.c The usual shower of singleton fixes and minor series all over MM, 2024-05-19 09:21:03 -07:00
oom_kill.c memory: remove the now superfluous sentinel element from ctl_table array 2024-04-25 20:56:32 -07:00
page-writeback.c The usual shower of singleton fixes and minor series all over MM, 2024-05-19 09:21:03 -07:00
page_alloc.c mm: page_alloc: fix highatomic typing in multi-block buddies 2024-06-05 19:19:25 -07:00
page_counter.c
page_ext.c mm: make page_ext_get() take a const argument 2024-04-25 20:56:14 -07:00
page_idle.c
page_io.c mm: drop the 'anon_' prefix for swap-out mTHP counters 2024-06-05 19:19:23 -07:00
page_isolation.c mm: page_isolation: prepare for hygienic freelists 2024-04-25 20:56:04 -07:00
page_owner.c mm/page-owner: use gfp_nested_mask() instead of open coded masking 2024-05-19 14:40:44 -07:00
page_poison.c mm/page_poison: replace kmap_atomic() with kmap_local_page() 2023-12-10 16:51:50 -08:00
page_reporting.c mm, treewide: rename MAX_ORDER to MAX_PAGE_ORDER 2024-01-08 15:27:15 -08:00
page_reporting.h
page_table_check.c mm/page_table_check: support userfault wr-protect entries 2024-05-05 17:53:41 -07:00
page_vma_mapped.c mm: make page_mapped_in_vma conditional on CONFIG_MEMORY_FAILURE 2024-05-05 17:53:45 -07:00
pagewalk.c mm: pagewalk: assert write mmap lock only for walking the user page tables 2023-12-10 16:51:53 -08:00
percpu-internal.h mm: percpu: add codetag reference into pcpuobj_ext 2024-04-25 20:55:56 -07:00
percpu-km.c
percpu-stats.c
percpu-vm.c percpu: clean up all mappings when pcpu_map_pages() fails 2024-04-25 20:55:49 -07:00
percpu.c mm: percpu: enable per-cpu allocation tagging 2024-04-25 20:55:56 -07:00
pgalloc-track.h
pgtable-generic.c mm: fix race between __split_huge_pmd_locked() and GUP-fast 2024-05-07 10:37:00 -07:00
process_vm_access.c mm: fix process_vm_rw page counts 2023-12-10 16:51:39 -08:00
ptdump.c mm: ptdump: add check_wx_pages debugfs attribute 2024-02-22 10:24:47 -08:00
readahead.c The usual shower of singleton fixes and minor series all over MM, 2024-05-19 09:21:03 -07:00
rmap.c mm: do not update memcg stats for NR_{FILE/SHMEM}_PMDMAPPED 2024-05-11 15:41:35 -07:00
rodata_test.c
secretmem.c mm/secretmem: use a folio in secretmem_fault() 2023-08-21 13:38:02 -07:00
shmem.c The usual shower of singleton fixes and minor series all over MM, 2024-05-19 09:21:03 -07:00
shmem_quota.c tmpfs: fix race on handling dquot rbtree 2024-03-26 11:07:23 -07:00
show_mem.c lib: add memory allocations report in show_mem() 2024-04-25 20:55:57 -07:00
shrinker.c mm: shrinker: use kvzalloc_node() from expand_one_shrinker_info() 2024-01-05 09:58:32 -08:00
shrinker_debug.c mm: shrinker: convert shrinker_rwsem to mutex 2023-10-04 10:32:26 -07:00
shuffle.c
shuffle.h mm, treewide: rename MAX_ORDER to MAX_PAGE_ORDER 2024-01-08 15:27:15 -08:00
slab.h The usual shower of singleton fixes and minor series all over MM, 2024-05-19 09:21:03 -07:00
slab_common.c The usual shower of singleton fixes and minor series all over MM, 2024-05-19 09:21:03 -07:00
slub.c codetag: avoid race at alloc_slab_obj_exts 2024-06-05 19:19:26 -07:00
sparse-vmemmap.c mm/vmemmap: allow architectures to override how vmemmap optimization works 2023-08-18 10:12:53 -07:00
sparse.c mm/sparse: guard the size of mem_section is power of 2 2024-05-05 17:53:40 -07:00
swap.c mm: add kernel-doc for folio_mark_accessed() 2024-05-05 17:53:50 -07:00
swap.h mm/swap: fix race when skipping swapcache 2024-02-20 14:20:48 -08:00
swap_cgroup.c
swap_slots.c mm: swap: update get_swap_pages() to take folio order 2024-04-25 20:56:37 -07:00
swap_state.c mm: remove struct page from get_shadow_from_swap_cache 2024-04-25 20:56:40 -07:00
swapfile.c getting rid of bogus set_blocksize() uses, switching it 2024-05-21 08:34:51 -07:00
truncate.c mm: convert pagecache_isize_extended to use a folio 2024-04-25 20:56:43 -07:00
usercopy.c
userfaultfd.c The usual shower of singleton fixes and minor series all over MM, 2024-05-19 09:21:03 -07:00
util.c mm: switch mm->get_unmapped_area() to a flag 2024-04-25 20:56:25 -07:00
vmalloc.c vmalloc: check CONFIG_EXECMEM in is_vmalloc_or_module_addr() 2024-06-05 19:19:25 -07:00
vmpressure.c eventfd: simplify eventfd_signal() 2023-11-28 14:08:38 +01:00
vmscan.c mm: drop the 'anon_' prefix for swap-out mTHP counters 2024-06-05 19:19:23 -07:00
vmstat.c iommu: observability of the IOMMU allocations 2024-04-15 14:31:47 +02:00
workingset.c mm: cleanup WORKINGSET_NODES in workingset 2024-05-07 10:36:59 -07:00
z3fold.c mm: zpool: return pool size in pages 2024-04-25 20:55:48 -07:00
zbud.c mm: zpool: return pool size in pages 2024-04-25 20:55:48 -07:00
zpool.c mm: zpool: return pool size in pages 2024-04-25 20:55:48 -07:00
zsmalloc.c mm: zpool: return pool size in pages 2024-04-25 20:55:48 -07:00
zswap.c mm: zswap: remove same_filled module params 2024-05-05 17:53:38 -07:00