The patch titled
Subject: ntfs: do not dereference a null ctx on error
has been added to the -mm mm-nonmm-unstable branch. Its filename is
ntfs-do-not-dereference-a-null-ctx-on-error.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/ntfs-do-not-dereference-a-null-ctx-on-error.patch
This patch will later appear in the mm-nonmm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Danila Chernetsov <listdansp@xxxxxxx>
Subject: ntfs: do not dereference a null ctx on error
Date: Fri, 7 Apr 2023 19:44:33 +0000
In ntfs_mft_data_extend_allocation_nolock(), if an error condition occurs
prior to 'ctx' being set to a non-NULL value, avoid dereferencing the NULL
'ctx' pointer in error handling.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Link: https://lkml.kernel.org/r/20230407194433.25659-1-listdansp@xxxxxxx
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Danila Chernetsov <listdansp@xxxxxxx>
Cc: Anton Altaparmakov <anton@xxxxxxxxxx>
Cc: Bagas Sanjaya <bagasdotme@xxxxxxxxx>
Cc: Konstantin Komarov <almaz.alexandrovich@xxxxxxxxxxxxxxxxxxxx>
Cc: Christian Brauner <brauner@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/ntfs/mft.c | 38 +++++++++++++++++++++-----------------
1 file changed, 21 insertions(+), 17 deletions(-)
--- a/fs/ntfs/mft.c~ntfs-do-not-dereference-a-null-ctx-on-error
+++ a/fs/ntfs/mft.c
@@ -1955,36 +1955,40 @@ undo_alloc:
"attribute.%s", es);
NVolSetErrors(vol);
}
- a = ctx->attr;
+
if (ntfs_rl_truncate_nolock(vol, &mft_ni->runlist, old_last_vcn)) {
ntfs_error(vol->sb, "Failed to truncate mft data attribute "
"runlist.%s", es);
NVolSetErrors(vol);
}
- if (mp_rebuilt && !IS_ERR(ctx->mrec)) {
- if (ntfs_mapping_pairs_build(vol, (u8*)a + le16_to_cpu(
+ if (ctx) {
+ a = ctx->attr;
+ if (mp_rebuilt && !IS_ERR(ctx->mrec)) {
+ if (ntfs_mapping_pairs_build(vol, (u8*)a + le16_to_cpu(
a->data.non_resident.mapping_pairs_offset),
old_alen - le16_to_cpu(
- a->data.non_resident.mapping_pairs_offset),
+ a->data.non_resident.mapping_pairs_offset),
rl2, ll, -1, NULL)) {
- ntfs_error(vol->sb, "Failed to restore mapping pairs "
+ ntfs_error(vol->sb, "Failed to restore mapping pairs "
"array.%s", es);
- NVolSetErrors(vol);
- }
- if (ntfs_attr_record_resize(ctx->mrec, a, old_alen)) {
- ntfs_error(vol->sb, "Failed to restore attribute "
+ NVolSetErrors(vol);
+ }
+ if (ntfs_attr_record_resize(ctx->mrec, a, old_alen)) {
+ ntfs_error(vol->sb, "Failed to restore attribute "
"record.%s", es);
- NVolSetErrors(vol);
+ NVolSetErrors(vol);
+ }
+ flush_dcache_mft_record_page(ctx->ntfs_ino);
+ mark_mft_record_dirty(ctx->ntfs_ino);
}
- flush_dcache_mft_record_page(ctx->ntfs_ino);
- mark_mft_record_dirty(ctx->ntfs_ino);
- } else if (IS_ERR(ctx->mrec)) {
- ntfs_error(vol->sb, "Failed to restore attribute search "
+ else if (IS_ERR(ctx->mrec)) {
+ ntfs_error(vol->sb, "Failed to restore attribute search "
"context.%s", es);
- NVolSetErrors(vol);
+ NVolSetErrors(vol);
+ }
+ if (ctx)
+ ntfs_attr_put_search_ctx(ctx);
}
- if (ctx)
- ntfs_attr_put_search_ctx(ctx);
if (!IS_ERR(mrec))
unmap_mft_record(mft_ni);
up_write(&mft_ni->runlist.lock);
_
Patches currently in -mm which might be from listdansp@xxxxxxx are
ntfs-do-not-dereference-a-null-ctx-on-error.patch
