| Message ID | 20201001005804.25641-1-cai@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | pipe: Fix memory leaks in create_pipe_files() | expand |
On Wed, Sep 30, 2020 at 08:58:04PM -0400, Qian Cai wrote: > Fixes: c73be61cede5 ("pipe: Add general notification queue support") > Signed-off-by: Qian Cai <cai@redhat.com> > --- > fs/pipe.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/fs/pipe.c b/fs/pipe.c > index 60dbee457143..5184972cd9c0 100644 > --- a/fs/pipe.c > +++ b/fs/pipe.c > @@ -920,10 +920,13 @@ int create_pipe_files(struct file **res, int flags) > if (flags & O_NOTIFICATION_PIPE) { > #ifdef CONFIG_WATCH_QUEUE > if (watch_queue_init(inode->i_pipe) < 0) { > + free_pipe_info(inode->i_pipe); > iput(inode); > return -ENOMEM; > } > #else > + free_pipe_info(inode->i_pipe); > + iput(inode); > return -ENOPKG; > #endif > } yeccchhhh... This is too ugly to live. 1) get rid of that sodding ifdef; define watch_queue_init() to fail if CONFIG_WATCH_QUEUE is not defined. 2) do not ignore the return value.
diff --git a/fs/pipe.c b/fs/pipe.c index 60dbee457143..5184972cd9c0 100644 --- a/fs/pipe.c +++ b/fs/pipe.c @@ -920,10 +920,13 @@ int create_pipe_files(struct file **res, int flags) if (flags & O_NOTIFICATION_PIPE) { #ifdef CONFIG_WATCH_QUEUE if (watch_queue_init(inode->i_pipe) < 0) { + free_pipe_info(inode->i_pipe); iput(inode); return -ENOMEM; } #else + free_pipe_info(inode->i_pipe); + iput(inode); return -ENOPKG; #endif }
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 <cai@redhat.com> --- fs/pipe.c | 3 +++ 1 file changed, 3 insertions(+)