diff options
| author | Björn Töpel <bjorn.topel@intel.com> | 2019-03-13 15:15:49 +0100 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2019-03-16 01:27:51 +0100 |
| commit | 044175a06706d516aa42874bb44dbbfc3c4d20eb (patch) | |
| tree | 3f937ac758c9a92675819eb56c77dada33e92880 /net/xdp | |
| parent | 895383983eee35743e535a08f4fa41c0f9e1382b (diff) | |
| download | lwn-044175a06706d516aa42874bb44dbbfc3c4d20eb.tar.gz lwn-044175a06706d516aa42874bb44dbbfc3c4d20eb.zip | |
xsk: fix umem memory leak on cleanup
When the umem is cleaned up, the task that created it might already be
gone. If the task was gone, the xdp_umem_release function did not free
the pages member of struct xdp_umem.
It turned out that the task lookup was not needed at all; The code was
a left-over when we moved from task accounting to user accounting [1].
This patch fixes the memory leak by removing the task lookup logic
completely.
[1] https://lore.kernel.org/netdev/20180131135356.19134-3-bjorn.topel@gmail.com/
Link: https://lore.kernel.org/netdev/c1cb2ca8-6a14-3980-8672-f3de0bb38dfd@suse.cz/
Fixes: c0c77d8fb787 ("xsk: add user memory registration support sockopt")
Reported-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Diffstat (limited to 'net/xdp')
| -rw-r--r-- | net/xdp/xdp_umem.c | 19 |
1 files changed, 1 insertions, 18 deletions
diff --git a/net/xdp/xdp_umem.c b/net/xdp/xdp_umem.c index 77520eacee8f..989e52386c35 100644 --- a/net/xdp/xdp_umem.c +++ b/net/xdp/xdp_umem.c @@ -193,9 +193,6 @@ static void xdp_umem_unaccount_pages(struct xdp_umem *umem) static void xdp_umem_release(struct xdp_umem *umem) { - struct task_struct *task; - struct mm_struct *mm; - xdp_umem_clear_dev(umem); ida_simple_remove(&umem_ida, umem->id); @@ -214,21 +211,10 @@ static void xdp_umem_release(struct xdp_umem *umem) xdp_umem_unpin_pages(umem); - task = get_pid_task(umem->pid, PIDTYPE_PID); - put_pid(umem->pid); - if (!task) - goto out; - mm = get_task_mm(task); - put_task_struct(task); - if (!mm) - goto out; - - mmput(mm); kfree(umem->pages); umem->pages = NULL; xdp_umem_unaccount_pages(umem); -out: kfree(umem); } @@ -357,7 +343,6 @@ static int xdp_umem_reg(struct xdp_umem *umem, struct xdp_umem_reg *mr) if (size_chk < 0) return -EINVAL; - umem->pid = get_task_pid(current, PIDTYPE_PID); umem->address = (unsigned long)addr; umem->chunk_mask = ~((u64)chunk_size - 1); umem->size = size; @@ -373,7 +358,7 @@ static int xdp_umem_reg(struct xdp_umem *umem, struct xdp_umem_reg *mr) err = xdp_umem_account_pages(umem); if (err) - goto out; + return err; err = xdp_umem_pin_pages(umem); if (err) @@ -392,8 +377,6 @@ static int xdp_umem_reg(struct xdp_umem *umem, struct xdp_umem_reg *mr) out_account: xdp_umem_unaccount_pages(umem); -out: - put_pid(umem->pid); return err; } |