From: Peter Lieven <pl@kamp.de>
Date: Sat, 15 Mar 2014 16:11:27 +0000 (+0100)
Subject: {pread,pwrite}_async: fix potential segfault in out of memory condition
X-Git-Tag: upstream/1.9.6^2~76^2~1
X-Git-Url: https://git.piment-noir.org/?a=commitdiff_plain;h=ae8168b3eb2325bd50d2a9e73717b5bf1dcb80eb;p=deb_libnfs.git

{pread,pwrite}_async: fix potential segfault in out of memory condition

if there are already requests in flight we cannot return with an error immediately
from the functions since the caller will likely tidy up his data structures directly
and later on we call his callback with private_data that has likely already
been freed.

Signed-off-by: Peter Lieven <pl@kamp.de>
---

diff --git a/lib/libnfs.c b/lib/libnfs.c
index 9fdbd0d..285e6dc 100644
--- a/lib/libnfs.c
+++ b/lib/libnfs.c
@@ -1605,7 +1605,7 @@ static void nfs_pread_mcb(struct rpc_context *rpc, int status, void *command_dat
 						return;
 					} else {
 						rpc_set_error(nfs->rpc, "RPC error: Failed to send READ call for %s", data->path);
-						data->error = 1;
+						data->oom = 1;
 					}
 				}
 			}
@@ -1683,9 +1683,11 @@ int nfs_pread_async(struct nfs_context *nfs, struct nfsfh *nfsfh, uint64_t offse
 		mdata = malloc(sizeof(struct nfs_mcb_data));
 		if (mdata == NULL) {
 			rpc_set_error(nfs->rpc, "out of memory: failed to allocate nfs_mcb_data structure");
-			if (data->num_calls == 0)
+			if (data->num_calls == 0) {
 				free_nfs_cb_data(data);
-			return -1;
+				return -1;
+			}
+			data->oom = 1;
 		}
 		memset(mdata, 0, sizeof(struct nfs_mcb_data));
 		mdata->data   = data;
@@ -1696,11 +1698,12 @@ int nfs_pread_async(struct nfs_context *nfs, struct nfsfh *nfsfh, uint64_t offse
 
 		if (rpc_nfs3_read_async(nfs->rpc, nfs_pread_mcb, &args, mdata) != 0) {
 			rpc_set_error(nfs->rpc, "RPC error: Failed to send READ call for %s", data->path);
-			data->cb(-ENOMEM, nfs, rpc_get_error(nfs->rpc), data->private_data);
 			free(mdata);
-			if (data->num_calls == 0)
+			if (data->num_calls == 0) {
 				free_nfs_cb_data(data);
-			return -1;
+				return -1;
+			}
+			data->oom = 1;
 		}
 
 		count               -= readcount;
@@ -1778,7 +1781,7 @@ static void nfs_pwrite_mcb(struct rpc_context *rpc, int status, void *command_da
 						return;
 					} else {
 						rpc_set_error(nfs->rpc, "RPC error: Failed to send WRITE call for %s", data->path);
-						data->error = 1;
+						data->oom = 1;
 					}
 				}
 			}
@@ -1796,7 +1799,11 @@ static void nfs_pwrite_mcb(struct rpc_context *rpc, int status, void *command_da
 		/* still waiting for more replies */
 		return;
 	}
-
+	if (data->oom != 0) {
+		data->cb(-ENOMEM, nfs, command_data, data->private_data);
+		free_nfs_cb_data(data);
+		return;
+	}
 	if (data->error != 0) {
 		data->cb(-EFAULT, nfs, command_data, data->private_data);
 		free_nfs_cb_data(data);
@@ -1855,9 +1862,11 @@ int nfs_pwrite_async(struct nfs_context *nfs, struct nfsfh *nfsfh, uint64_t offs
 		mdata = malloc(sizeof(struct nfs_mcb_data));
 		if (mdata == NULL) {
 			rpc_set_error(nfs->rpc, "out of memory: failed to allocate nfs_mcb_data structure");
-			if (data->num_calls == 0)
+			if (data->num_calls == 0) {
 				free_nfs_cb_data(data);
-			return -1;
+				return -1;
+			}
+			data->oom = 1;
 		}
 		memset(mdata, 0, sizeof(struct nfs_mcb_data));
 		mdata->data   = data;
@@ -1868,12 +1877,12 @@ int nfs_pwrite_async(struct nfs_context *nfs, struct nfsfh *nfsfh, uint64_t offs
 
 		if (rpc_nfs3_write_async(nfs->rpc, nfs_pwrite_mcb, &args, mdata) != 0) {
 			rpc_set_error(nfs->rpc, "RPC error: Failed to send WRITE call for %s", data->path);
-			data->cb(-ENOMEM, nfs, rpc_get_error(nfs->rpc), data->private_data);
 			free(mdata);
-			if (data->num_calls == 0)
+			if (data->num_calls == 0) {
 				free_nfs_cb_data(data);
-
-			return -1;
+				return -1;
+			}
+			data->oom = 1;
 		}
 
 		count               -= writecount;