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authorBjörn Töpel <bjorn.topel@intel.com>2019-03-13 15:15:49 +0100
committerDaniel Borkmann <daniel@iogearbox.net>2019-03-16 01:27:51 +0100
commit044175a06706d516aa42874bb44dbbfc3c4d20eb (patch)
tree3f937ac758c9a92675819eb56c77dada33e92880
parentMerge branch 'fix-bpf-docs' (diff)
downloadlinux-dev-044175a06706d516aa42874bb44dbbfc3c4d20eb.tar.xz
linux-dev-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>
-rw-r--r--include/net/xdp_sock.h1
-rw-r--r--net/xdp/xdp_umem.c19
2 files changed, 1 insertions, 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;
}