leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity

io_uring: fix leaking reg files on exit

Browse Source 
If io_sqe_files_unregister() faults on io_rsrc_ref_quiesce(), it will
fail to do unregister leaving files referenced. And that may well happen
because of a strayed signal or just because it does allocations inside.

In io_ring_ctx_free() do an unsafe version of unregister, as it's
guaranteed to not have requests by that point and so quiesce is useless.

Cc: stable@vger.kernel.org
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/e696e9eade571b51997d0dc1d01f144c6d685c05.1618278933.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Pavel Begunkov 2021-04-13 02:58:38 +01:00 committed by Jens Axboe
parent f70865db5f
commit 084804002e
1 changed files with 15 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

29
fs/io_uring.c
View File

@ -7089,6 +7089,10 @@ static void __io_sqe_files_unregister(struct io_ring_ctx *ctx)
fput(file);
}
#endif
io_free_file_tables(&ctx->file_table, ctx->nr_user_files);
kfree(ctx->file_data);
ctx->file_data = NULL;
ctx->nr_user_files = 0;
}
static inline void io_rsrc_ref_lock(struct io_ring_ctx *ctx)
@ -7195,21 +7199,14 @@ static struct io_rsrc_data *io_rsrc_data_alloc(struct io_ring_ctx *ctx,
static int io_sqe_files_unregister(struct io_ring_ctx *ctx)
{
struct io_rsrc_data *data = ctx->file_data;
int ret;
if (!data)
if (!ctx->file_data)
return -ENXIO;
ret = io_rsrc_ref_quiesce(data, ctx);
if (ret)
return ret;
__io_sqe_files_unregister(ctx);
io_free_file_tables(&ctx->file_table, ctx->nr_user_files);
kfree(data);
ctx->file_data = NULL;
ctx->nr_user_files = 0;
return 0;
ret = io_rsrc_ref_quiesce(ctx->file_data, ctx);
if (!ret)
__io_sqe_files_unregister(ctx);
return ret;
}
static void io_sq_thread_unpark(struct io_sq_data *sqd)
@ -7659,7 +7656,7 @@ static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
ret = io_sqe_files_scm(ctx);
if (ret) {
io_sqe_files_unregister(ctx);
__io_sqe_files_unregister(ctx);
return ret;
}
@ -8460,7 +8457,11 @@ static void io_ring_ctx_free(struct io_ring_ctx *ctx)
}
mutex_lock(&ctx->uring_lock);
io_sqe_files_unregister(ctx);
if (ctx->file_data) {
if (!atomic_dec_and_test(&ctx->file_data->refs))
wait_for_completion(&ctx->file_data->done);
__io_sqe_files_unregister(ctx);
}
if (ctx->rings)
__io_cqring_overflow_flush(ctx, true);
mutex_unlock(&ctx->uring_lock);