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| author | Mike Rapoport (IBM) <rppt@kernel.org> | 2023-07-28 12:55:12 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2023-07-28 18:47:06 +0200 |
| commit | c442a957b2f4e116f28aeb55bf2719cb7bb2ad60 (patch) | |
| tree | 57c58428e498890f33de234b88c85a3293bf7592 /mm | |
| parent | mm/mempolicy: Take VMA lock before replacing policy (diff) | |
| download | linux-c442a957b2f4e116f28aeb55bf2719cb7bb2ad60.tar.xz linux-c442a957b2f4e116f28aeb55bf2719cb7bb2ad60.zip | |
Revert "mm,memblock: reset memblock.reserved to system init state to prevent UAF"
This reverts commit 9e46e4dcd9d6cd88342b028dbfa5f4fb7483d39c.
kbuild reports a warning in memblock_remove_region() because of a false
positive caused by partial reset of the memblock state.
Doing the full reset will remove the false positives, but will allow
late use of memblock_free() to go unnoticed, so it is better to revert
the offending commit.
WARNING: CPU: 0 PID: 1 at mm/memblock.c:352 memblock_remove_region (kbuild/src/x86_64/mm/memblock.c:352 (discriminator 1))
Modules linked in:
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.5.0-rc3-00001-g9e46e4dcd9d6 #2
RIP: 0010:memblock_remove_region (kbuild/src/x86_64/mm/memblock.c:352 (discriminator 1))
Call Trace:
memblock_discard (kbuild/src/x86_64/mm/memblock.c:383)
page_alloc_init_late (kbuild/src/x86_64/include/linux/find.h:208 kbuild/src/x86_64/include/linux/nodemask.h:266 kbuild/src/x86_64/mm/mm_init.c:2405)
kernel_init_freeable (kbuild/src/x86_64/init/main.c:1325 kbuild/src/x86_64/init/main.c:1546)
kernel_init (kbuild/src/x86_64/init/main.c:1439)
ret_from_fork (kbuild/src/x86_64/arch/x86/kernel/process.c:145)
ret_from_fork_asm (kbuild/src/x86_64/arch/x86/entry/entry_64.S:298)
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202307271656.447aa17e-oliver.sang@intel.com
Signed-off-by: "Mike Rapoport (IBM)" <rppt@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/memblock.c | 4 |
1 files changed, 0 insertions, 4 deletions
diff --git a/mm/memblock.c b/mm/memblock.c index c39b36378f5d..f9e61e565a53 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -374,10 +374,6 @@ void __init memblock_discard(void) kfree(memblock.reserved.regions); else memblock_free_late(addr, size); - /* Reset to prevent UAF from stray frees. */ - memblock.reserved.regions = memblock_reserved_init_regions; - memblock.reserved.cnt = 1; - memblock_remove_region(&memblock.reserved, 0); } if (memblock.memory.regions != memblock_memory_init_regions) { |