From: Björn Töpel <bjorn.to...@intel.com> 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.to...@gmail.com/ Link: https://lore.kernel.org/netdev/c1cb2ca8-6a14-3980-8672-f3de0bb38...@suse.cz/ Fixes: c0c77d8fb787 ("xsk: add user memory registration support sockopt") Reported-by: Jiri Slaby <jsl...@suse.cz> Signed-off-by: Björn Töpel <bjorn.to...@intel.com> --- include/net/xdp_sock.h | 1 - net/xdp/xdp_umem.c | 19 +------------------ 2 files changed, 1 insertion(+), 19 deletions(-) diff --git a/include/net/xdp_sock.h b/include/net/xdp_sock.h index 61cf7dbb6782..d074b6d60f8a 100644 --- a/include/net/xdp_sock.h +++ b/include/net/xdp_sock.h @@ -36,7 +36,6 @@ struct xdp_umem { u32 headroom; u32 chunk_size_nohr; struct user_struct *user; - struct pid *pid; unsigned long address; refcount_t users; struct work_struct work; 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; } -- 2.19.1
