From: =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= <bjorn.topel@intel.com>
Date: Wed, 13 Mar 2019 15:15:49 +0100
Subject: xsk: fix umem memory leak on cleanup
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Patch-mainline: v5.1-rc1
Git-commit: 044175a06706d516aa42874bb44dbbfc3c4d20eb
References: bnc#1129030
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: Jiri Slaby <jslaby@suse.cz>
---
include/net/xdp_sock.h | 1 -
net/xdp/xdp_umem.c | 19 +------------------
2 files changed, 1 insertion(+), 19 deletions(-)
--- 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;
--- a/net/xdp/xdp_umem.c
+++ b/net/xdp/xdp_umem.c
@@ -189,9 +189,6 @@ static void xdp_umem_unaccount_pages(str
static void xdp_umem_release(struct xdp_umem *umem)
{
- struct task_struct *task;
- struct mm_struct *mm;
-
xdp_umem_clear_dev(umem);
if (umem->fq) {
@@ -208,21 +205,10 @@ static void xdp_umem_release(struct xdp_
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);
}
@@ -351,7 +337,6 @@ static int xdp_umem_reg(struct xdp_umem
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;
@@ -367,7 +352,7 @@ static int xdp_umem_reg(struct xdp_umem
err = xdp_umem_account_pages(umem);
if (err)
- goto out;
+ return err;
err = xdp_umem_pin_pages(umem);
if (err)
@@ -386,8 +371,6 @@ static int xdp_umem_reg(struct xdp_umem
out_account:
xdp_umem_unaccount_pages(umem);
-out:
- put_pid(umem->pid);
return err;
}