[PATCH] Fix a panic in vfs_fruit
Volker Lendecke
Volker.Lendecke at SerNet.DE
Mon Aug 20 18:45:59 UTC 2018
Hi!
Review appreciated!
Thanks, Volker
--
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-------------- next part --------------
From 5770c84f66cb346c30e848591a2e8a0c2816d758 Mon Sep 17 00:00:00 2001
From: Volker Lendecke <vl at samba.org>
Date: Mon, 6 Aug 2018 14:33:34 +0200
Subject: [PATCH 1/2] vfs_fruit: Fix a leak of "br_lck"
Fix a panic if fruit_access_check detects a locking conflict.
do_lock() returns a valid br_lck even in case of a locking conflict.
Not free'ing it leads to a invalid lock order panic later, because
"br_lck" corresponds to a dbwrap lock on brlock.tdb.
Signed-off-by: Volker Lendecke <vl at samba.org>
---
source3/modules/vfs_fruit.c | 24 ++++++++++++++++--------
1 file changed, 16 insertions(+), 8 deletions(-)
diff --git a/source3/modules/vfs_fruit.c b/source3/modules/vfs_fruit.c
index 191477c0e1d..9635116e0ba 100644
--- a/source3/modules/vfs_fruit.c
+++ b/source3/modules/vfs_fruit.c
@@ -2386,7 +2386,6 @@ static NTSTATUS fruit_check_access(vfs_handle_struct *handle,
uint32_t deny_mode)
{
NTSTATUS status = NT_STATUS_OK;
- struct byte_range_lock *br_lck = NULL;
bool open_for_reading, open_for_writing, deny_read, deny_write;
off_t off;
bool have_read = false;
@@ -2444,6 +2443,8 @@ static NTSTATUS fruit_check_access(vfs_handle_struct *handle,
/* Set locks */
if ((access_mask & FILE_READ_DATA) && have_read) {
+ struct byte_range_lock *br_lck = NULL;
+
off = access_to_netatalk_brl(fork_type, FILE_READ_DATA);
br_lck = do_lock(
handle->conn->sconn->msg_ctx, fsp,
@@ -2451,13 +2452,16 @@ static NTSTATUS fruit_check_access(vfs_handle_struct *handle,
READ_LOCK, POSIX_LOCK, false,
&status, NULL);
+ TALLOC_FREE(br_lck);
+
if (!NT_STATUS_IS_OK(status)) {
return status;
}
- TALLOC_FREE(br_lck);
}
if ((deny_mode & DENY_READ) && have_read) {
+ struct byte_range_lock *br_lck = NULL;
+
off = denymode_to_netatalk_brl(fork_type, DENY_READ);
br_lck = do_lock(
handle->conn->sconn->msg_ctx, fsp,
@@ -2465,10 +2469,11 @@ static NTSTATUS fruit_check_access(vfs_handle_struct *handle,
READ_LOCK, POSIX_LOCK, false,
&status, NULL);
+ TALLOC_FREE(br_lck);
+
if (!NT_STATUS_IS_OK(status)) {
return status;
}
- TALLOC_FREE(br_lck);
}
}
@@ -2494,6 +2499,8 @@ static NTSTATUS fruit_check_access(vfs_handle_struct *handle,
/* Set locks */
if ((access_mask & FILE_WRITE_DATA) && have_read) {
+ struct byte_range_lock *br_lck = NULL;
+
off = access_to_netatalk_brl(fork_type, FILE_WRITE_DATA);
br_lck = do_lock(
handle->conn->sconn->msg_ctx, fsp,
@@ -2501,13 +2508,15 @@ static NTSTATUS fruit_check_access(vfs_handle_struct *handle,
READ_LOCK, POSIX_LOCK, false,
&status, NULL);
+ TALLOC_FREE(br_lck);
+
if (!NT_STATUS_IS_OK(status)) {
return status;
}
- TALLOC_FREE(br_lck);
-
}
if ((deny_mode & DENY_WRITE) && have_read) {
+ struct byte_range_lock *br_lck = NULL;
+
off = denymode_to_netatalk_brl(fork_type, DENY_WRITE);
br_lck = do_lock(
handle->conn->sconn->msg_ctx, fsp,
@@ -2515,15 +2524,14 @@ static NTSTATUS fruit_check_access(vfs_handle_struct *handle,
READ_LOCK, POSIX_LOCK, false,
&status, NULL);
+ TALLOC_FREE(br_lck);
+
if (!NT_STATUS_IS_OK(status)) {
return status;
}
- TALLOC_FREE(br_lck);
}
}
- TALLOC_FREE(br_lck);
-
return status;
}
--
2.11.0
From ef8f5e7000fdbfdbdaa8103f1f77abf8c35cc00e Mon Sep 17 00:00:00 2001
From: Volker Lendecke <vl at samba.org>
Date: Mon, 6 Aug 2018 14:35:15 +0200
Subject: [PATCH 2/2] torture: Demonstrate the invalid lock order panic
Signed-off-by: Volker Lendecke <vl at samba.org>
---
source4/torture/vfs/fruit.c | 89 +++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 89 insertions(+)
diff --git a/source4/torture/vfs/fruit.c b/source4/torture/vfs/fruit.c
index 25c0668ea5d..a9ae891a23f 100644
--- a/source4/torture/vfs/fruit.c
+++ b/source4/torture/vfs/fruit.c
@@ -4936,6 +4936,93 @@ done:
return ret;
}
+static bool test_fruit_locking_conflict(struct torture_context *tctx,
+ struct smb2_tree *tree)
+{
+ TALLOC_CTX *mem_ctx;
+ struct smb2_create create;
+ struct smb2_handle h;
+ struct smb2_lock lck;
+ struct smb2_lock_element el;
+ const char *fname = BASEDIR "\\locking_conflict.txt";
+ NTSTATUS status;
+ bool ret = false;
+
+ mem_ctx = talloc_new(tctx);
+ torture_assert_not_null(tctx, mem_ctx, "talloc_new failed");
+
+ /* clean slate ...*/
+ smb2_util_unlink(tree, fname);
+ smb2_deltree(tree, fname);
+ smb2_deltree(tree, BASEDIR);
+
+ status = torture_smb2_testdir(tree, BASEDIR, &h);
+ CHECK_STATUS(status, NT_STATUS_OK);
+ smb2_util_close(tree, h);
+
+ create = (struct smb2_create) {
+ .in.desired_access = SEC_RIGHTS_FILE_READ,
+ .in.file_attributes = FILE_ATTRIBUTE_NORMAL,
+ .in.share_access =
+ NTCREATEX_SHARE_ACCESS_READ|
+ NTCREATEX_SHARE_ACCESS_WRITE,
+ .in.create_disposition = NTCREATEX_DISP_CREATE,
+ .in.impersonation_level = SMB2_IMPERSONATION_ANONYMOUS,
+ .in.fname = fname,
+ };
+
+ status = smb2_create(tree, mem_ctx, &create);
+ CHECK_STATUS(status, NT_STATUS_OK);
+ h = create.out.file.handle;
+
+ el = (struct smb2_lock_element) {
+ .offset = 0xfffffffffffffffc,
+ .length = 1,
+ .flags = SMB2_LOCK_FLAG_EXCLUSIVE,
+ };
+ lck = (struct smb2_lock) {
+ .in.lock_count = 1,
+ .in.file.handle = h,
+ .in.locks = &el,
+ };
+
+ status = smb2_lock(tree, &lck);
+ CHECK_STATUS(status, NT_STATUS_OK);
+
+ el = (struct smb2_lock_element) {
+ .offset = 0,
+ .length = 0x7fffffffffffffff,
+ .flags = SMB2_LOCK_FLAG_EXCLUSIVE,
+ };
+ status = smb2_lock(tree, &lck);
+ CHECK_STATUS(status, NT_STATUS_OK);
+
+ create = (struct smb2_create) {
+ .in.desired_access =
+ SEC_RIGHTS_FILE_READ|SEC_RIGHTS_FILE_WRITE,
+ .in.file_attributes = FILE_ATTRIBUTE_NORMAL,
+ .in.share_access = NTCREATEX_SHARE_ACCESS_READ,
+ .in.create_disposition = NTCREATEX_DISP_OPEN,
+ .in.impersonation_level = SMB2_IMPERSONATION_ANONYMOUS,
+ .in.fname = fname,
+ };
+
+ status = smb2_create(tree, mem_ctx, &create);
+ CHECK_STATUS(status, NT_STATUS_FILE_LOCK_CONFLICT);
+
+ {
+ struct smb2_close cl = {
+ .level = RAW_CLOSE_SMB2,
+ .in.file.handle = h,
+ };
+ smb2_close(tree, &cl);
+ }
+
+ ret = true;
+done:
+ return ret;
+}
+
struct torture_suite *torture_vfs_fruit_netatalk(TALLOC_CTX *ctx)
{
struct torture_suite *suite = torture_suite_create(
@@ -4945,6 +5032,8 @@ struct torture_suite *torture_vfs_fruit_netatalk(TALLOC_CTX *ctx)
torture_suite_add_1smb2_test(suite, "read netatalk metadata", test_read_netatalk_metadata);
torture_suite_add_1smb2_test(suite, "stream names with locally created xattr", test_stream_names_local);
+ torture_suite_add_1smb2_test(
+ suite, "locking conflict", test_fruit_locking_conflict);
return suite;
}
--
2.11.0
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