From: Jens Axboe <axboe@kernel.dk>
To: io-uring@vger.kernel.org
Cc: Jens Axboe <axboe@kernel.dk>,
syzbot+f4ebcc98223dafd8991e@syzkaller.appspotmail.com
Subject: [PATCH 10/18] io_uring: fix error path cleanup in io_sqe_files_register()
Date: Fri, 16 Oct 2020 10:02:16 -0600 [thread overview]
Message-ID: <20201016160224.1575329-11-axboe@kernel.dk> (raw)
In-Reply-To: <20201016160224.1575329-1-axboe@kernel.dk>
syzbot reports the following crash:
general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 1 PID: 8927 Comm: syz-executor.3 Not tainted 5.9.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:io_file_from_index fs/io_uring.c:5963 [inline]
RIP: 0010:io_sqe_files_register fs/io_uring.c:7369 [inline]
RIP: 0010:__io_uring_register fs/io_uring.c:9463 [inline]
RIP: 0010:__do_sys_io_uring_register+0x2fd2/0x3ee0 fs/io_uring.c:9553
Code: ec 03 49 c1 ee 03 49 01 ec 49 01 ee e8 57 61 9c ff 41 80 3c 24 00 0f 85 9b 09 00 00 4d 8b af b8 01 00 00 4c 89 e8 48 c1 e8 03 <80> 3c 28 00 0f 85 76 09 00 00 49 8b 55 00 89 d8 c1 f8 09 48 98 4c
RSP: 0018:ffffc90009137d68 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffc9000ef2a000
RDX: 0000000000040000 RSI: ffffffff81d81dd9 RDI: 0000000000000005
RBP: dffffc0000000000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffed1012882a37
R13: 0000000000000000 R14: ffffed1012882a38 R15: ffff888094415000
FS: 00007f4266f3c700(0000) GS:ffff8880ae500000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000118c000 CR3: 000000008e57d000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45de59
Code: 0d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f4266f3bc78 EFLAGS: 00000246 ORIG_RAX: 00000000000001ab
RAX: ffffffffffffffda RBX: 00000000000083c0 RCX: 000000000045de59
RDX: 0000000020000280 RSI: 0000000000000002 RDI: 0000000000000005
RBP: 000000000118bf68 R08: 0000000000000000 R09: 0000000000000000
R10: 40000000000000a1 R11: 0000000000000246 R12: 000000000118bf2c
R13: 00007fff2fa4f12f R14: 00007f4266f3c9c0 R15: 000000000118bf2c
Modules linked in:
---[ end trace 2a40a195e2d5e6e6 ]---
RIP: 0010:io_file_from_index fs/io_uring.c:5963 [inline]
RIP: 0010:io_sqe_files_register fs/io_uring.c:7369 [inline]
RIP: 0010:__io_uring_register fs/io_uring.c:9463 [inline]
RIP: 0010:__do_sys_io_uring_register+0x2fd2/0x3ee0 fs/io_uring.c:9553
Code: ec 03 49 c1 ee 03 49 01 ec 49 01 ee e8 57 61 9c ff 41 80 3c 24 00 0f 85 9b 09 00 00 4d 8b af b8 01 00 00 4c 89 e8 48 c1 e8 03 <80> 3c 28 00 0f 85 76 09 00 00 49 8b 55 00 89 d8 c1 f8 09 48 98 4c
RSP: 0018:ffffc90009137d68 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffc9000ef2a000
RDX: 0000000000040000 RSI: ffffffff81d81dd9 RDI: 0000000000000005
RBP: dffffc0000000000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffed1012882a37
R13: 0000000000000000 R14: ffffed1012882a38 R15: ffff888094415000
FS: 00007f4266f3c700(0000) GS:ffff8880ae400000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000074a918 CR3: 000000008e57d000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
which is a copy of fget failure condition jumping to cleanup, but the
cleanup requires ctx->file_data to be assigned. Assign it when setup,
and ensure that we clear it again for the error path exit.
Fixes: 5398ae698525 ("io_uring: clean file_data access in files_register")
Reported-by: syzbot+f4ebcc98223dafd8991e@syzkaller.appspotmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
fs/io_uring.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 632f4e21569c..2c83c2688ec5 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -7282,6 +7282,7 @@ static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
if (io_sqe_alloc_file_tables(file_data, nr_tables, nr_args))
goto out_ref;
+ ctx->file_data = file_data;
for (i = 0; i < nr_args; i++, ctx->nr_user_files++) {
struct fixed_file_table *table;
@@ -7316,7 +7317,6 @@ static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
table->files[index] = file;
}
- ctx->file_data = file_data;
ret = io_sqe_files_scm(ctx);
if (ret) {
io_sqe_files_unregister(ctx);
@@ -7349,6 +7349,7 @@ static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
out_free:
kfree(file_data->table);
kfree(file_data);
+ ctx->file_data = NULL;
return ret;
}
--
2.28.0
next prev parent reply other threads:[~2020-10-16 16:02 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-16 16:02 [PATCHES 0/10] Fixes queued up for 5.10 Jens Axboe
2020-10-16 16:02 ` [PATCH 01/18] io_uring: Fix sizeof() mismatch Jens Axboe
2020-10-16 16:02 ` [PATCH 02/18] readahead: use limited read-ahead to satisfy read Jens Axboe
2020-10-16 16:02 ` [PATCH 03/18] io_uring: don't clear IOCB_NOWAIT for async buffered retry Jens Axboe
2020-10-16 16:02 ` [PATCH 04/18] io_uring: don't set COMP_LOCKED if won't put Jens Axboe
2020-10-16 16:02 ` [PATCH 05/18] io_uring: don't unnecessarily clear F_LINK_TIMEOUT Jens Axboe
2020-10-16 16:02 ` [PATCH 06/18] io_uring: don't put a poll req under spinlock Jens Axboe
2020-10-16 16:02 ` [PATCH 07/18] io_uring: dig out COMP_LOCK from deep call chain Jens Axboe
2020-10-16 16:02 ` [PATCH 08/18] io_uring: fix REQ_F_COMP_LOCKED by killing it Jens Axboe
2020-10-16 16:02 ` [PATCH 09/18] Revert "io_uring: mark io_uring_fops/io_op_defs as __read_mostly" Jens Axboe
2020-10-16 16:02 ` Jens Axboe [this message]
2020-10-16 16:02 ` [PATCH 11/18] io-wq: assign NUMA node locality if appropriate Jens Axboe
2020-10-16 16:02 ` [PATCH 12/18] io_uring: pass required context in as flags Jens Axboe
2020-10-16 16:02 ` [PATCH 13/18] io_uring: rely solely on work flags to determine personality Jens Axboe
2020-10-16 16:02 ` [PATCH 14/18] io_uring: move io identity items into separate struct Jens Axboe
2020-10-16 16:02 ` [PATCH 15/18] io_uring: COW io_identity on mismatch Jens Axboe
2020-10-16 16:02 ` [PATCH 16/18] io_uring: store io_identity in io_uring_task Jens Axboe
2020-10-16 16:02 ` [PATCH 17/18] io_uring: assign new io_identity for task if members have changed Jens Axboe
2020-10-16 16:02 ` [PATCH 18/18] io_uring: use percpu counters to track inflight requests Jens Axboe
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