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| author | Lorenzo Stoakes <lorenzo.stoakes@oracle.com> | 2024-11-18 16:17:26 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-11-22 15:37:34 +0100 |
| commit | 77b50f617a4b4c6f2ddee41df92a23d9a35629b9 (patch) | |
| tree | c652142537463662c0a4360b0899d5f3fcdde500 /mm/util.c | |
| parent | 7443f3e11254f94a16b48d38b0a9e9b659e006bf (diff) | |
| download | linux-77b50f617a4b4c6f2ddee41df92a23d9a35629b9.tar.gz linux-77b50f617a4b4c6f2ddee41df92a23d9a35629b9.tar.bz2 linux-77b50f617a4b4c6f2ddee41df92a23d9a35629b9.zip | |
mm: unconditionally close VMAs on error
[ Upstream commit 4080ef1579b2413435413988d14ac8c68e4d42c8 ]
Incorrect invocation of VMA callbacks when the VMA is no longer in a
consistent state is bug prone and risky to perform.
With regards to the important vm_ops->close() callback We have gone to
great lengths to try to track whether or not we ought to close VMAs.
Rather than doing so and risking making a mistake somewhere, instead
unconditionally close and reset vma->vm_ops to an empty dummy operations
set with a NULL .close operator.
We introduce a new function to do so - vma_close() - and simplify existing
vms logic which tracked whether we needed to close or not.
This simplifies the logic, avoids incorrect double-calling of the .close()
callback and allows us to update error paths to simply call vma_close()
unconditionally - making VMA closure idempotent.
Link: https://lkml.kernel.org/r/28e89dda96f68c505cb6f8e9fc9b57c3e9f74b42.1730224667.git.lorenzo.stoakes@oracle.com
Fixes: deb0f6562884 ("mm/mmap: undo ->mmap() when arch_validate_flags() fails")
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reported-by: Jann Horn <jannh@google.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reviewed-by: Jann Horn <jannh@google.com>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Helge Deller <deller@gmx.de>
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Will Deacon <will@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'mm/util.c')
| -rw-r--r-- | mm/util.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/mm/util.c b/mm/util.c index 15f1970da665..d3a2877c176f 100644 --- a/mm/util.c +++ b/mm/util.c @@ -1121,6 +1121,21 @@ int mmap_file(struct file *file, struct vm_area_struct *vma) return err; } +void vma_close(struct vm_area_struct *vma) +{ + static const struct vm_operations_struct dummy_vm_ops = {}; + + if (vma->vm_ops && vma->vm_ops->close) { + vma->vm_ops->close(vma); + + /* + * The mapping is in an inconsistent state, and no further hooks + * may be invoked upon it. + */ + vma->vm_ops = &dummy_vm_ops; + } +} + #ifdef CONFIG_PRINTK /** * mem_dump_obj - Print available provenance information |