From: Danila Chernetsov listdansp@mail.ru
[ Upstream commit aa4b92c5234878d55da96d387ea4d3695ca5e4ab ]
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.
Signed-off-by: Danila Chernetsov listdansp@mail.ru Reviewed-by: Namjae Jeon linkinjeon@kernel.org Signed-off-by: Christian Brauner brauner@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- fs/ntfs/mft.c | 36 +++++++++++++++++++----------------- 1 file changed, 19 insertions(+), 17 deletions(-)
diff --git a/fs/ntfs/mft.c b/fs/ntfs/mft.c index 48030899dc6ec..0155f106ec344 100644 --- a/fs/ntfs/mft.c +++ b/fs/ntfs/mft.c @@ -1955,36 +1955,38 @@ static int ntfs_mft_data_extend_allocation_nolock(ntfs_volume *vol) "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); + } + 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 " + "context.%s", es); NVolSetErrors(vol); } - 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 " - "context.%s", es); - NVolSetErrors(vol); - } - if (ctx) ntfs_attr_put_search_ctx(ctx); + } if (!IS_ERR(mrec)) unmap_mft_record(mft_ni); up_write(&mft_ni->runlist.lock);