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| author | Ryan Roberts <ryan.roberts@arm.com> | 2025-10-03 16:52:36 +0100 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2025-10-07 14:01:12 -0700 |
| commit | 28bba2c2935e219d6cb6946e16b9a0b7c47913be (patch) | |
| tree | c7c9d9a2e854370d5ba4a8bbd5ba7f3ed7455daa /mm/util.c | |
| parent | f04aad36a07cc17b7a5d5b9a2d386ce6fae63e93 (diff) | |
| download | linux-28bba2c2935e219d6cb6946e16b9a0b7c47913be.tar.gz | |
fsnotify: pass correct offset to fsnotify_mmap_perm()
fsnotify_mmap_perm() requires a byte offset for the file about to be
mmap'ed. But it is called from vm_mmap_pgoff(), which has a page offset.
Previously the conversion was done incorrectly so let's fix it, being
careful not to overflow on 32-bit platforms.
Discovered during code review.
Link: https://lkml.kernel.org/r/20251003155238.2147410-1-ryan.roberts@arm.com
Fixes: 066e053fe208 ("fsnotify: add pre-content hooks on mmap()")
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Reviewed-by: Kiryl Shutsemau <kas@kernel.org>
Cc: Amir Goldstein <amir73il@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/util.c')
| -rw-r--r-- | mm/util.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/mm/util.c b/mm/util.c index 6c1d64ed02211f..8989d576752861 100644 --- a/mm/util.c +++ b/mm/util.c @@ -566,6 +566,7 @@ unsigned long vm_mmap_pgoff(struct file *file, unsigned long addr, unsigned long len, unsigned long prot, unsigned long flag, unsigned long pgoff) { + loff_t off = (loff_t)pgoff << PAGE_SHIFT; unsigned long ret; struct mm_struct *mm = current->mm; unsigned long populate; @@ -573,7 +574,7 @@ unsigned long vm_mmap_pgoff(struct file *file, unsigned long addr, ret = security_mmap_file(file, prot, flag); if (!ret) - ret = fsnotify_mmap_perm(file, prot, pgoff >> PAGE_SHIFT, len); + ret = fsnotify_mmap_perm(file, prot, off, len); if (!ret) { if (mmap_write_lock_killable(mm)) return -EINTR; |