2020-10-01 02:55:49

by Qian Cai

[permalink] [raw]
Subject: [PATCH v2] pipe: Fix memory leaks in create_pipe_files()

Calling pipe2() with O_NOTIFICATION_PIPE could results in memory leaks
in an error path or CONFIG_WATCH_QUEUE=n. Plug them.

unreferenced object 0xc00000141114a0d8 (size 992):
comm "trinity-c61", pid 1353192, jiffies 4296255779 (age 25989.560s)
hex dump (first 32 bytes):
80 11 00 00 e8 03 00 00 00 00 00 00 00 00 00 00 ................
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
backtrace:
[<00000000abff13d7>] kmem_cache_alloc+0x1b4/0x470
[<000000009502e5d5>] alloc_inode+0xd0/0x130
[<00000000ca1c1a21>] new_inode_pseudo+0x1c/0x80
new_inode_pseudo at fs/inode.c:932
[<000000000c01d1d6>] create_pipe_files+0x48/0x2d0
get_pipe_inode at fs/pipe.c:874
(inlined by) create_pipe_files at fs/pipe.c:914
[<00000000d13ff4c4>] __do_pipe_flags+0x50/0x120
__do_pipe_flags at fs/pipe.c:965
[<0000000003941e42>] do_pipe2+0x3c/0x100
do_pipe2 at fs/pipe.c:1013
[<00000000a006b818>] sys_pipe2+0x1c/0x30
__se_sys_pipe2 at fs/pipe.c:1028
[<00000000a6925b55>] system_call_exception+0xf8/0x1d0
[<000000001c6b0740>] system_call_common+0xe8/0x218
unreferenced object 0xc000001f575ce600 (size 512):
comm "trinity-c61", pid 1353192, jiffies 4296255779 (age 25989.560s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 ad 4e ad de .............N..
ff ff ff ff 00 00 00 00 ff ff ff ff ff ff ff ff ................
backtrace:
[<00000000d74d5e3a>] kmem_cache_alloc_trace+0x1c4/0x2d0
[<0000000061cbc9cb>] alloc_pipe_info+0x88/0x2c0
kmalloc at include/linux/slab.h:554
(inlined by) kzalloc at include/linux/slab.h:666
(inlined by) alloc_pipe_info at fs/pipe.c:793
[<00000000efd6129c>] create_pipe_files+0x6c/0x2d0
get_pipe_inode at fs/pipe.c:883
(inlined by) create_pipe_files at fs/pipe.c:914
[<00000000d13ff4c4>] __do_pipe_flags+0x50/0x120
[<0000000003941e42>] do_pipe2+0x3c/0x100
[<00000000a006b818>] sys_pipe2+0x1c/0x30
[<00000000a6925b55>] system_call_exception+0xf8/0x1d0
[<000000001c6b0740>] system_call_common+0xe8/0x218
unreferenced object 0xc000000d94f20400 (size 1024):
comm "trinity-c61", pid 1353192, jiffies 4296255779 (age 25989.560s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<00000000e60ee00f>] __kmalloc+0x1e4/0x330
[<00000000130e8cc8>] alloc_pipe_info+0x154/0x2c0
kmalloc_array at include/linux/slab.h:594
(inlined by) kcalloc at include/linux/slab.h:605
(inlined by) alloc_pipe_info at fs/pipe.c:810
[<00000000efd6129c>] create_pipe_files+0x6c/0x2d0
[<00000000d13ff4c4>] __do_pipe_flags+0x50/0x120
[<0000000003941e42>] do_pipe2+0x3c/0x100
[<00000000a006b818>] sys_pipe2+0x1c/0x30
[<00000000a6925b55>] system_call_exception+0xf8/0x1d0
[<000000001c6b0740>] system_call_common+0xe8/0x218

Fixes: c73be61cede5 ("pipe: Add general notification queue support")
Signed-off-by: Qian Cai <[email protected]>
---
fs/pipe.c | 11 +++++------
include/linux/watch_queue.h | 4 ++++
2 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/fs/pipe.c b/fs/pipe.c
index 60dbee457143..6fbfbb8f32e1 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -913,19 +913,18 @@ int create_pipe_files(struct file **res, int flags)
{
struct inode *inode = get_pipe_inode();
struct file *f;
+ int ret;

if (!inode)
return -ENFILE;

if (flags & O_NOTIFICATION_PIPE) {
-#ifdef CONFIG_WATCH_QUEUE
- if (watch_queue_init(inode->i_pipe) < 0) {
+ ret = watch_queue_init(inode->i_pipe);
+ if (ret < 0) {
+ free_pipe_info(inode->i_pipe);
iput(inode);
- return -ENOMEM;
+ return ret;
}
-#else
- return -ENOPKG;
-#endif
}

f = alloc_file_pseudo(inode, pipe_mnt, "",
diff --git a/include/linux/watch_queue.h b/include/linux/watch_queue.h
index 5e08db2adc31..20665fbe0552 100644
--- a/include/linux/watch_queue.h
+++ b/include/linux/watch_queue.h
@@ -123,5 +123,9 @@ static inline void remove_watch_list(struct watch_list *wlist, u64 id)
#define watch_sizeof(STRUCT) (sizeof(STRUCT) << WATCH_INFO_LENGTH__SHIFT)

#endif
+static inline int watch_queue_init(struct pipe_inode_info *pipe)
+{
+ return -ENOPKG;
+}

#endif /* _LINUX_WATCH_QUEUE_H */
--
2.28.0


2020-10-01 03:06:41

by Eric Biggers

[permalink] [raw]
Subject: Re: [PATCH v2] pipe: Fix memory leaks in create_pipe_files()

On Wed, Sep 30, 2020 at 10:52:55PM -0400, Qian Cai wrote:
> diff --git a/include/linux/watch_queue.h b/include/linux/watch_queue.h
> index 5e08db2adc31..20665fbe0552 100644
> --- a/include/linux/watch_queue.h
> +++ b/include/linux/watch_queue.h
> @@ -123,5 +123,9 @@ static inline void remove_watch_list(struct watch_list *wlist, u64 id)
> #define watch_sizeof(STRUCT) (sizeof(STRUCT) << WATCH_INFO_LENGTH__SHIFT)
>
> #endif
> +static inline int watch_queue_init(struct pipe_inode_info *pipe)
> +{
> + return -ENOPKG;
> +}

This needs to be conditional on !CONFIG_WATCH_QUEUE.

- Eric

2020-10-01 07:08:33

by kernel test robot

[permalink] [raw]
Subject: Re: [PATCH v2] pipe: Fix memory leaks in create_pipe_files()

Hi Qian,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on linus/master]
[also build test ERROR on v5.9-rc7 next-20200930]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url: https://github.com/0day-ci/linux/commits/Qian-Cai/pipe-Fix-memory-leaks-in-create_pipe_files/20201001-105501
base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 60e720931556fc1034d0981460164dcf02697679
config: xtensa-allyesconfig (attached as .config)
compiler: xtensa-linux-gcc (GCC) 9.3.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/0day-ci/linux/commit/40f946bea0970bf1dfa7a9f020e9ad7ec9f1f67d
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Qian-Cai/pipe-Fix-memory-leaks-in-create_pipe_files/20201001-105501
git checkout 40f946bea0970bf1dfa7a9f020e9ad7ec9f1f67d
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=xtensa

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <[email protected]>

All errors (new ones prefixed by >>):

In file included from kernel/watch_queue.c:27:
>> include/linux/watch_queue.h:126:19: error: static declaration of 'watch_queue_init' follows non-static declaration
126 | static inline int watch_queue_init(struct pipe_inode_info *pipe)
| ^~~~~~~~~~~~~~~~
include/linux/watch_queue.h:91:12: note: previous declaration of 'watch_queue_init' was here
91 | extern int watch_queue_init(struct pipe_inode_info *);
| ^~~~~~~~~~~~~~~~
kernel/watch_queue.c:648:5: error: redefinition of 'watch_queue_init'
648 | int watch_queue_init(struct pipe_inode_info *pipe)
| ^~~~~~~~~~~~~~~~
In file included from kernel/watch_queue.c:27:
include/linux/watch_queue.h:126:19: note: previous definition of 'watch_queue_init' was here
126 | static inline int watch_queue_init(struct pipe_inode_info *pipe)
| ^~~~~~~~~~~~~~~~
--
In file included from fs/pipe.c:27:
>> include/linux/watch_queue.h:126:19: error: static declaration of 'watch_queue_init' follows non-static declaration
126 | static inline int watch_queue_init(struct pipe_inode_info *pipe)
| ^~~~~~~~~~~~~~~~
include/linux/watch_queue.h:91:12: note: previous declaration of 'watch_queue_init' was here
91 | extern int watch_queue_init(struct pipe_inode_info *);
| ^~~~~~~~~~~~~~~~

vim +/watch_queue_init +126 include/linux/watch_queue.h

124
125 #endif
> 126 static inline int watch_queue_init(struct pipe_inode_info *pipe)
127 {
128 return -ENOPKG;
129 }
130

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/[email protected]


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