fs/ntfs3: validate dirty page table on log replay

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Each DIR_PAGE_ENTRY ends in a page_lcns[] array whose length is the on-disk
lcns_follow field. check_rstbl() validates the table bookkeeping but never
checks that this array fits in the entry, so a crafted lcns_follow lets the
v0->v1 conversion memmove and later replay passes run off the entry.

Add check_dp_table() to reject, right after check_rstbl(), any entry larger
than its size claims via struct_size() (the same expression used to allocate
these entries, so the check is overflow-safe by construction). All consumers
can then trust lcns_follow as the real capacity. This covers every
page_lcns[] access whose index is bounded by the entry itself (the
conversion memmove, the HotFix store via find_dp(), and the self-bounded
scan loops). Accesses whose index comes from the log record need a separate
bound and are handled in a follow-up patch.

Fixes: b46acd6a6a ("fs/ntfs3: Add NTFS journal")
Cc: stable@vger.kernel.org
Reported-by: Weiming Shi <bestswngs@gmail.com>
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Xiang Mei <xmei5@asu.edu>
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>

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Xiang Mei 2026-06-17 16:13:42 -07:00 • committed by Konstantin Komarov

parent 111f8d74a1

commit 006cb7713d

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fs/ntfs3/fslog.c

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