patch attached to set ppath to null by default
On Sat, Jun 4, 2022 at 12:22 AM Steven French
<Steven.French@xxxxxxxxxxxxx> wrote:
>
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> Get Outlook for Android
> ________________________________
> From: kernel test robot <lkp@xxxxxxxxx>
> Sent: Friday, June 3, 2022 10:00:31 PM
> To: pc <pc@xxxxxx>
> Cc: llvm@xxxxxxxxxxxxxxx <llvm@xxxxxxxxxxxxxxx>; kbuild-all@xxxxxxxxxxxx <kbuild-all@xxxxxxxxxxxx>; linux-cifs@xxxxxxxxxxxxxxx <linux-cifs@xxxxxxxxxxxxxxx>; samba-technical@xxxxxxxxxxxxxxx <samba-technical@xxxxxxxxxxxxxxx>; Steven French <Steven.French@xxxxxxxxxxxxx>
> Subject: [EXTERNAL] [cifs:for-next 8/8] fs/cifs/dfs_cache.c:1294:2: warning: variable 'ppath' is used uninitialized whenever 'if' condition is false
>
> tree: git://git.samba.org/sfrench/cifs-2.6.git for-next
> head: ef605e86821253d16d47a02ce1f766a461614fef
> commit: ef605e86821253d16d47a02ce1f766a461614fef [8/8] cifs: skip trailing separators of prefix paths
> config: arm-randconfig-c002-20220603 (https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdownload.01.org%2F0day-ci%2Farchive%2F20220604%2F202206041223.Kx81JSQt-lkp%40intel.com%2Fconfig&data=05%7C01%7CSteven.French%40microsoft.com%7C8fd0f93076304ca4db7408da45e74210%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C637899156811777573%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=I%2FEylneaMr3LmxdLWgGMfgoePbuxH5tathKlIaR5dJU%3D&reserved=0)
> compiler: clang version 15.0.0 (https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fllvm%2Fllvm-project&data=05%7C01%7CSteven.French%40microsoft.com%7C8fd0f93076304ca4db7408da45e74210%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C637899156811777573%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=IIT72ydb3VXEpUd8pYus96zzwjWnvHcHJgP4uFbLI2U%3D&reserved=0 b364c76683f8ef241025a9556300778c07b590c2)
> reproduce (this is a W=1 build):
> wget https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fraw.githubusercontent.com%2Fintel%2Flkp-tests%2Fmaster%2Fsbin%2Fmake.cross&data=05%7C01%7CSteven.French%40microsoft.com%7C8fd0f93076304ca4db7408da45e74210%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C637899156811777573%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=rWO79li71JswarF6XxfENQwmBdCbcQ4sG5m%2FhQCcl3M%3D&reserved=0 -O ~/bin/make.cross
> chmod +x ~/bin/make.cross
> # install arm cross compiling tool for clang build
> # apt-get install binutils-arm-linux-gnueabi
> git remote add cifs git://git.samba.org/sfrench/cifs-2.6.git
> git fetch --no-tags cifs for-next
> git checkout ef605e86821253d16d47a02ce1f766a461614fef
> # save the config file
> mkdir build_dir && cp config build_dir/.config
> COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=arm SHELL=/bin/bash fs/cifs/
>
> If you fix the issue, kindly add following tag where applicable
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
>
> All warnings (new ones prefixed by >>):
>
> >> fs/cifs/dfs_cache.c:1294:2: warning: variable 'ppath' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
> if (target_pplen || dfsref_pplen) {
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> include/linux/compiler.h:56:28: note: expanded from macro 'if'
> #define if(cond, ...) if ( __trace_if_var( !!(cond , ## __VA_ARGS__) ) )
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> include/linux/compiler.h:58:30: note: expanded from macro '__trace_if_var'
> #define __trace_if_var(cond) (__builtin_constant_p(cond) ? (cond) : __trace_if_value(cond))
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> fs/cifs/dfs_cache.c:1307:12: note: uninitialized use occurs here
> *prefix = ppath;
> ^~~~~
> fs/cifs/dfs_cache.c:1294:2: note: remove the 'if' if its condition is always true
> if (target_pplen || dfsref_pplen) {
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> include/linux/compiler.h:56:23: note: expanded from macro 'if'
> #define if(cond, ...) if ( __trace_if_var( !!(cond , ## __VA_ARGS__) ) )
> ^
> fs/cifs/dfs_cache.c:1270:28: note: initialize the variable 'ppath' to silence this warning
> char *target_share, *ppath;
> ^
> = NULL
> 1 warning generated.
>
>
> vim +1294 fs/cifs/dfs_cache.c
>
> 1255
> 1256 /**
> 1257 * dfs_cache_get_tgt_share - parse a DFS target
> 1258 *
> 1259 * @path: DFS full path
> 1260 * @it: DFS target iterator.
> 1261 * @share: tree name.
> 1262 * @prefix: prefix path.
> 1263 *
> 1264 * Return zero if target was parsed correctly, otherwise non-zero.
> 1265 */
> 1266 int dfs_cache_get_tgt_share(char *path, const struct dfs_cache_tgt_iterator *it, char **share,
> 1267 char **prefix)
> 1268 {
> 1269 char sep;
> 1270 char *target_share, *ppath;
> 1271 const char *target_ppath, *dfsref_ppath;
> 1272 size_t target_pplen, dfsref_pplen;
> 1273 size_t len, c;
> 1274
> 1275 if (!it || !path || !share || !prefix || strlen(path) < it->it_path_consumed)
> 1276 return -EINVAL;
> 1277
> 1278 sep = it->it_name[0];
> 1279 if (sep != '\\' && sep != '/')
> 1280 return -EINVAL;
> 1281
> 1282 target_ppath = parse_target_share(it->it_name, &target_share);
> 1283 if (IS_ERR(target_ppath))
> 1284 return PTR_ERR(target_ppath);
> 1285
> 1286 /* point to prefix in DFS referral path */
> 1287 dfsref_ppath = path + it->it_path_consumed;
> 1288 dfsref_ppath += strspn(dfsref_ppath, "/\\");
> 1289
> 1290 target_pplen = strlen(target_ppath);
> 1291 dfsref_pplen = strlen(dfsref_ppath);
> 1292
> 1293 /* merge prefix paths from DFS referral path and target node */
> > 1294 if (target_pplen || dfsref_pplen) {
> 1295 len = target_pplen + dfsref_pplen + 2;
> 1296 ppath = kzalloc(len, GFP_KERNEL);
> 1297 if (!ppath) {
> 1298 kfree(target_share);
> 1299 return -ENOMEM;
> 1300 }
> 1301 c = strscpy(ppath, target_ppath, len);
> 1302 if (c && dfsref_pplen)
> 1303 ppath[c] = sep;
> 1304 strlcat(ppath, dfsref_ppath, len);
> 1305 }
> 1306 *share = target_share;
> 1307 *prefix = ppath;
> 1308 return 0;
> 1309 }
> 1310
>
> --
> 0-DAY CI Kernel Test Service
> https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2F01.org%2Flkp&data=05%7C01%7CSteven.French%40microsoft.com%7C8fd0f93076304ca4db7408da45e74210%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C637899156811777573%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=DA%2FZslJz3uARiZHC0HxgSP3ccOYqv%2B%2FUh68fCZm3Fgk%3D&reserved=0
--
Thanks,
Steve
From 46ce69662169e10ff621aea0e368d30abbe6ac99 Mon Sep 17 00:00:00 2001
From: Steve French <stfrench@xxxxxxxxxxxxx>
Date: Sat, 4 Jun 2022 01:18:37 -0500
Subject: [PATCH] cifs: fix uninitialized pointer in error case in
dfs_cache_get_tgt_share
Set default value of ppath to null.
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
---
fs/cifs/dfs_cache.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/fs/cifs/dfs_cache.c b/fs/cifs/dfs_cache.c
index 7b978a126268..34a8f3baed5e 100644
--- a/fs/cifs/dfs_cache.c
+++ b/fs/cifs/dfs_cache.c
@@ -1267,7 +1267,8 @@ int dfs_cache_get_tgt_share(char *path, const struct dfs_cache_tgt_iterator *it,
char **prefix)
{
char sep;
- char *target_share, *ppath;
+ char *target_share;
+ char *ppath = NULL;
const char *target_ppath, *dfsref_ppath;
size_t target_pplen, dfsref_pplen;
size_t len, c;
--
2.34.1
