linux/mm
Vasily Averin 10c8d69f31 mm/swapfile.c: swap_next should increase position index
If seq_file .next fuction does not change position index, read after
some lseek can generate unexpected output.

In Aug 2018 NeilBrown noticed commit 1f4aace60b ("fs/seq_file.c:
simplify seq_file iteration code and interface") "Some ->next functions
do not increment *pos when they return NULL...  Note that such ->next
functions are buggy and should be fixed.  A simple demonstration is

  dd if=/proc/swaps bs=1000 skip=1

Choose any block size larger than the size of /proc/swaps.  This will
always show the whole last line of /proc/swaps"

Described problem is still actual.  If you make lseek into middle of
last output line following read will output end of last line and whole
last line once again.

  $ dd if=/proc/swaps bs=1  # usual output
  Filename				Type		Size	Used	Priority
  /dev/dm-0                               partition	4194812	97536	-2
  104+0 records in
  104+0 records out
  104 bytes copied

  $ dd if=/proc/swaps bs=40 skip=1    # last line was generated twice
  dd: /proc/swaps: cannot skip to specified offset
  v/dm-0                               partition	4194812	97536	-2
  /dev/dm-0                               partition	4194812	97536	-2
  3+1 records in
  3+1 records out
  131 bytes copied

https://bugzilla.kernel.org/show_bug.cgi?id=206283

Link: http://lkml.kernel.org/r/bd8cfd7b-ac95-9b91-f9e7-e8438bd5047d@virtuozzo.com
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Jann Horn <jannh@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Kees Cook <keescook@chromium.org>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-01-31 10:30:38 -08:00
..
kasan x86/kasan: Print original address on #GP 2019-12-31 13:15:38 +01:00
backing-dev.c memcg: fix a crash in wb_workfn when a device disappears 2020-01-31 10:30:36 -08:00
balloon_compaction.c mm/balloon_compaction: suppress allocation warnings 2019-09-04 07:42:01 -04:00
cleancache.c Driver Core and debugfs changes for 5.3-rc1 2019-07-12 12:24:03 -07:00
cma_debug.c mm/cma_debug.c: use DEFINE_DEBUGFS_ATTRIBUTE to define debugfs fops 2019-12-01 12:59:09 -08:00
cma.c mm/cma.c: switch to bitmap_zalloc() for cma bitmap allocation 2019-12-01 12:59:09 -08:00
cma.h
compaction.c mm, compaction: fix wrong pfn handling in __reset_isolation_pfn() 2019-10-14 15:04:01 -07:00
debug_page_ref.c
debug.c mm/debug.c: always print flags in dump_page() 2020-01-31 10:30:36 -08:00
dmapool.c mm: security: introduce init_on_alloc=1 and init_on_free=1 boot options 2019-07-12 11:05:46 -07:00
early_ioremap.c
fadvise.c fs: Export generic_fadvise() 2019-08-30 22:43:58 -07:00
failslab.c mm/failslab.c: by default, do not fail allocations with direct reclaim only 2019-07-12 11:05:43 -07:00
filemap.c mm/filemap.c: clean up filemap_write_and_wait() 2020-01-31 10:30:37 -08:00
frame_vector.c mm: untag user pointers in get_vaddr_frames 2019-09-25 17:51:41 -07:00
frontswap.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 482 2019-06-19 17:09:52 +02:00
gup_benchmark.c mm/gup_benchmark: use proper FOLL_WRITE flags instead of hard-coding "1" 2020-01-31 10:30:38 -08:00
gup.c mm, tree-wide: rename put_user_page*() to unpin_user_page*() 2020-01-31 10:30:38 -08:00
highmem.c mm, x86/mm: Untangle address space layout definitions from basic pgtable type definitions 2019-12-10 10:12:55 +01:00
hmm.c mm/hmm: remove hmm_range_dma_map and hmm_range_dma_unmap 2019-11-23 19:56:45 -04:00
huge_memory.c mm/huge_memory.c: thp: fix conflict of above-47bit hint address and PMD alignment 2020-01-13 18:19:01 -08:00
hugetlb_cgroup.c mm: hugetlb controller for cgroups v2 2019-12-16 12:41:40 -08:00
hugetlb.c mm/hugetlb: defer freeing of huge pages if in non-task context 2020-01-04 13:55:09 -08:00
hwpoison-inject.c mm/hwpoison-inject: use DEFINE_DEBUGFS_ATTRIBUTE to define debugfs fops 2019-12-01 12:59:09 -08:00
init-mm.c mm/init-mm.c: include <linux/mman.h> for vm_committed_as_batch 2019-10-19 06:32:32 -04:00
internal.h mm, pcpu: make zone pcp updates and reset internal to the mm 2019-12-01 12:59:06 -08:00
interval_tree.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 248 2019-06-19 17:09:08 +02:00
Kconfig mm/Kconfig: fix trivial help text punctuation 2019-12-01 12:59:10 -08:00
Kconfig.debug mm, page_owner, debug_pagealloc: save and dump freeing stack trace 2019-09-24 15:54:08 -07:00
khugepaged.c mm/thp: flush file for !is_shmem PageDirty() case in collapse_file() 2019-12-01 12:59:09 -08:00
kmemleak-test.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 333 2019-06-05 17:37:06 +02:00
kmemleak.c mm/kmemleak: turn kmemleak_lock and object->lock to raw_spinlock_t 2020-01-31 10:30:36 -08:00
ksm.c * PPC secure guest support 2019-12-04 11:08:30 -08:00
list_lru.c mm: memcg/slab: stop setting page->mem_cgroup pointer for slab pages 2019-07-12 11:05:44 -07:00
maccess.c uaccess: Add strict non-pagefault kernel-space read function 2019-11-02 12:39:12 -07:00
madvise.c mm: make do_madvise() available internally 2020-01-20 17:04:02 -07:00
Makefile mm: Add write-protect and clean utilities for address space ranges 2019-11-06 13:03:36 +01:00
mapping_dirty_helpers.c mm: Add write-protect and clean utilities for address space ranges 2019-11-06 13:03:36 +01:00
memblock.c mm: support memblock alloc on the exact node for sparse_buffer_init() 2019-12-01 12:59:08 -08:00
memcontrol.c mm: thp: don't need care deferred split queue in memcg charge move path 2020-01-31 10:30:36 -08:00
memfd.c mm: page cache: store only head pages in i_pages 2019-09-24 15:54:08 -07:00
memory_hotplug.c mm/memory_hotplug: fix remove_memory() lockdep splat 2020-01-31 10:30:36 -08:00
memory-failure.c mm/memory-failure.c: use page_shift() in add_to_kill() 2019-12-01 12:59:04 -08:00
memory.c Linux 5.5-rc3 2019-12-25 10:41:37 +01:00
mempolicy.c mm/mempolicy.c: fix out of bounds write in mpol_parse_str() 2020-01-31 10:30:36 -08:00
mempool.c docs/core-api/mm: fix return value descriptions in mm/ 2019-03-05 21:07:20 -08:00
memremap.c mm: devmap: refactor 1-based refcounting for ZONE_DEVICE pages 2020-01-31 10:30:37 -08:00
memtest.c
migrate.c mm: move_pages: report the number of non-attempted pages 2020-01-31 10:30:36 -08:00
mincore.c mm: untag user pointers passed to memory syscalls 2019-09-25 17:51:41 -07:00
mlock.c mm: untag user pointers passed to memory syscalls 2019-09-25 17:51:41 -07:00
mm_init.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
mmap.c The timekeeping and timers departement provides: 2020-01-27 16:47:05 -08:00
mmu_context.c
mmu_gather.c mm: remove quicklist page table caches 2019-09-24 15:54:09 -07:00
mmu_notifier.c mm/mmu_notifiers: Use 'interval_sub' as the variable for mmu_interval_notifier 2020-01-14 11:54:47 -04:00
mmzone.c
mprotect.c autonuma: reduce cache footprint when scanning page tables 2019-12-01 12:59:09 -08:00
mremap.c mm/mmap.c: use IS_ERR_VALUE to check return value of get_unmapped_area 2019-12-01 06:29:19 -08:00
msync.c mm: untag user pointers passed to memory syscalls 2019-09-25 17:51:41 -07:00
nommu.c mm/mmap.c: rb_parent is not necessary in __vma_link_list() 2019-12-01 06:29:19 -08:00
oom_kill.c mm/oom: fix pgtables units mismatch in Killed process message 2020-01-04 13:55:09 -08:00
page_alloc.c mm, debug_pagealloc: don't rely on static keys too early 2020-01-13 18:19:02 -08:00
page_counter.c memcg: introduce memory.min 2018-06-07 17:34:36 -07:00
page_ext.c mm, page_owner: fix off-by-one error in __set_page_owner_handle() 2019-10-14 15:04:00 -07:00
page_idle.c mm/page_idle.c: fix oops because end_pfn is larger than max_pfn 2019-06-29 16:43:45 +08:00
page_io.c mm/page_io.c: annotate refault stalls from swap_readpage 2019-12-01 12:59:11 -08:00
page_isolation.c mm/page_isolation.c: convert SKIP_HWPOISON to MEMORY_OFFLINE 2019-12-01 12:59:04 -08:00
page_owner.c mm/page_owner: don't access uninitialized memmaps when reading /proc/pagetypeinfo 2019-10-19 06:32:31 -04:00
page_poison.c mm/page_poison.c: fix a typo in a comment 2019-09-24 15:54:08 -07:00
page_vma_mapped.c mm: introduce page_size() 2019-09-24 15:54:08 -07:00
page-writeback.c mm/page-writeback.c: improve arithmetic divisions 2020-01-13 18:19:02 -08:00
pagewalk.c mm: Add a walk_page_mapping() function to the pagewalk code 2019-11-06 13:02:43 +01:00
percpu-internal.h percpu: convert chunk hints to be based on pcpu_block_md 2019-03-13 12:25:31 -07:00
percpu-km.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428 2019-06-05 17:37:16 +02:00
percpu-stats.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428 2019-06-05 17:37:16 +02:00
percpu-vm.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428 2019-06-05 17:37:16 +02:00
percpu.c bitmap: genericize percpu bitmap region iterators 2020-01-20 16:40:56 +01:00
pgtable-generic.c asm-generic/mm: stub out p{4,u}d_clear_bad() if __PAGETABLE_P{4,U}D_FOLDED 2019-12-01 06:29:19 -08:00
process_vm_access.c mm, tree-wide: rename put_user_page*() to unpin_user_page*() 2020-01-31 10:30:38 -08:00
readahead.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
rmap.c mm, thp: do not queue fully unmapped pages for deferred split 2019-12-01 12:59:09 -08:00
rodata_test.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 2019-06-05 17:37:17 +02:00
shmem.c mm/shmem.c: thp, shmem: fix conflict of above-47bit hint address and PMD alignment 2020-01-13 18:19:01 -08:00
shuffle.c mm: fix -Wmissing-prototypes warnings 2019-10-07 15:47:19 -07:00
shuffle.h mm: maintain randomization of page free lists 2019-05-14 19:52:48 -07:00
slab_common.c mm: memcg/slab: call flush_memcg_workqueue() only if memcg workqueue is valid 2020-01-13 18:19:02 -08:00
slab.c mm, debug_pagealloc: don't rely on static keys too early 2020-01-13 18:19:02 -08:00
slab.h mm: clean up and clarify lruvec lookup procedure 2019-12-01 12:59:06 -08:00
slob.c mm, sl[aou]b: guarantee natural alignment for kmalloc(power-of-two) 2019-10-07 15:47:20 -07:00
slub.c mm/slub.c: avoid slub allocation while holding list_lock 2020-01-31 10:30:36 -08:00
sparse-vmemmap.c mm/sparsemem: convert kmalloc_section_memmap() to populate_section_memmap() 2019-07-18 17:08:07 -07:00
sparse.c mm/sparse.c: reset section's mem_map when fully deactivated 2020-01-31 10:30:36 -08:00
swap_cgroup.c
swap_slots.c mm, swap, get_swap_pages: use entry_size instead of cluster in parameter 2018-08-22 10:52:44 -07:00
swap_state.c mm: page cache: store only head pages in i_pages 2019-09-24 15:54:08 -07:00
swap.c mm: devmap: refactor 1-based refcounting for ZONE_DEVICE pages 2020-01-31 10:30:37 -08:00
swapfile.c mm/swapfile.c: swap_next should increase position index 2020-01-31 10:30:38 -08:00
truncate.c mm/thp: allow dropping THP from page cache 2019-10-19 06:32:33 -04:00
usercopy.c usercopy: Avoid HIGHMEM pfn warning 2019-09-17 15:20:17 -07:00
userfaultfd.c mm: fix typos in comments when calling __SetPageUptodate() 2019-12-01 12:59:10 -08:00
util.c mm/mmap.c: rb_parent is not necessary in __vma_link_list() 2019-12-01 06:29:19 -08:00
vmacache.c mm: get rid of vmacache_flush_all() entirely 2018-09-13 15:18:04 -10:00
vmalloc.c Linux 5.5-rc7 2020-01-20 08:05:16 +01:00
vmpressure.c mm/vmpressure.c: fix a signedness bug in vmpressure_register_event() 2019-10-07 15:47:19 -07:00
vmscan.c mm: vmscan: protect shrinker idr replace with CONFIG_MEMCG 2019-12-17 20:59:59 -08:00
vmstat.c mm/memcontrol: use vmstat names for printing statistics 2019-12-04 19:44:11 -08:00
workingset.c mm: vmscan: detect file thrashing at the reclaim root 2019-12-01 12:59:07 -08:00
z3fold.c mm/z3fold.c: add inter-page compaction 2019-12-01 12:59:07 -08:00
zbud.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
zpool.c zpool: add malloc_support_movable to zpool_driver 2019-09-24 15:54:12 -07:00
zsmalloc.c mm/zsmalloc.c: fix the migrated zspage statistics. 2020-01-04 13:55:09 -08:00
zswap.c zswap: do not map same object twice 2019-09-24 15:54:12 -07:00