Messages in this thread | | | Date | Mon, 20 Nov 2023 17:31:53 +0200 | From | José Pekkarinen <> | Subject | Re: [PATCH] iov_iter: fix memleak in iov_iter_extract_pages |
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On 2023-11-11 09:53, José Pekkarinen wrote: > syzbot reports there is a memory leak in iov_iter_extract_pages where > in > the unlikely case of having an error in pin_user_pages_fast, the pages > aren't free. This patch will free it before returning. Output of mem > leak follows: > > BUG: memory leak > unreferenced object 0xffff888109d2e400 (size 1024): > comm "syz-executor121", pid 5006, jiffies 4294943225 (age 17.760s) > hex dump (first 32 bytes): > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > backtrace: > [<ffffffff81554bbb>] __do_kmalloc_node mm/slab_common.c:984 > [inline] > [<ffffffff81554bbb>] __kmalloc_node+0x4b/0x150 mm/slab_common.c:992 > [<ffffffff815440f9>] kmalloc_node include/linux/slab.h:602 [inline] > [<ffffffff815440f9>] kvmalloc_node+0x99/0x170 mm/util.c:604 > [<ffffffff824c52fe>] kvmalloc include/linux/slab.h:720 [inline] > [<ffffffff824c52fe>] kvmalloc_array include/linux/slab.h:738 > [inline] > [<ffffffff824c52fe>] want_pages_array lib/iov_iter.c:985 [inline] > [<ffffffff824c52fe>] iov_iter_extract_user_pages > lib/iov_iter.c:1765 [inline] > [<ffffffff824c52fe>] iov_iter_extract_pages+0x1ee/0xa40 > lib/iov_iter.c:1831 > [<ffffffff824125a7>] bio_map_user_iov+0x167/0x5d0 > block/blk-map.c:297 > [<ffffffff82412df3>] blk_rq_map_user_iov+0x3e3/0xb30 > block/blk-map.c:664 > [<ffffffff82413943>] blk_rq_map_user block/blk-map.c:691 [inline] > [<ffffffff82413943>] blk_rq_map_user_io+0x143/0x160 > block/blk-map.c:724 > [<ffffffff82ca0925>] sg_io+0x285/0x510 > drivers/scsi/scsi_ioctl.c:456 > [<ffffffff82ca1025>] scsi_cdrom_send_packet+0x1b5/0x480 > drivers/scsi/scsi_ioctl.c:820 > [<ffffffff82ca13ba>] scsi_ioctl+0xca/0xd30 > drivers/scsi/scsi_ioctl.c:903 > [<ffffffff82d35964>] sg_ioctl+0x5f4/0x10a0 drivers/scsi/sg.c:1163 > [<ffffffff8168e602>] vfs_ioctl fs/ioctl.c:51 [inline] > [<ffffffff8168e602>] __do_sys_ioctl fs/ioctl.c:870 [inline] > [<ffffffff8168e602>] __se_sys_ioctl fs/ioctl.c:856 [inline] > [<ffffffff8168e602>] __x64_sys_ioctl+0xf2/0x140 fs/ioctl.c:856 > [<ffffffff84ad2bb8>] do_syscall_x64 arch/x86/entry/common.c:50 > [inline] > [<ffffffff84ad2bb8>] do_syscall_64+0x38/0xb0 > arch/x86/entry/common.c:80 > [<ffffffff84c0008b>] entry_SYSCALL_64_after_hwframe+0x63/0xcd > > BUG: memory leak > unreferenced object 0xffff888109d2dc00 (size 1024): > comm "syz-executor121", pid 5007, jiffies 4294943747 (age 12.540s) > hex dump (first 32 bytes): > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > backtrace: > [<ffffffff81554bbb>] __do_kmalloc_node mm/slab_common.c:984 > [inline] > [<ffffffff81554bbb>] __kmalloc_node+0x4b/0x150 mm/slab_common.c:992 > [<ffffffff815440f9>] kmalloc_node include/linux/slab.h:602 [inline] > [<ffffffff815440f9>] kvmalloc_node+0x99/0x170 mm/util.c:604 > [<ffffffff824c52fe>] kvmalloc include/linux/slab.h:720 [inline] > [<ffffffff824c52fe>] kvmalloc_array include/linux/slab.h:738 > [inline] > [<ffffffff824c52fe>] want_pages_array lib/iov_iter.c:985 [inline] > [<ffffffff824c52fe>] iov_iter_extract_user_pages > lib/iov_iter.c:1765 [inline] > [<ffffffff824c52fe>] iov_iter_extract_pages+0x1ee/0xa40 > lib/iov_iter.c:1831 > [<ffffffff824125a7>] bio_map_user_iov+0x167/0x5d0 > block/blk-map.c:297 > [<ffffffff82412df3>] blk_rq_map_user_iov+0x3e3/0xb30 > block/blk-map.c:664 > [<ffffffff82413943>] blk_rq_map_user block/blk-map.c:691 [inline] > [<ffffffff82413943>] blk_rq_map_user_io+0x143/0x160 > block/blk-map.c:724 > [<ffffffff82ca0925>] sg_io+0x285/0x510 > drivers/scsi/scsi_ioctl.c:456 > [<ffffffff82ca1025>] scsi_cdrom_send_packet+0x1b5/0x480 > drivers/scsi/scsi_ioctl.c:820 > [<ffffffff82ca13ba>] scsi_ioctl+0xca/0xd30 > drivers/scsi/scsi_ioctl.c:903 > [<ffffffff82d35964>] sg_ioctl+0x5f4/0x10a0 drivers/scsi/sg.c:1163 > [<ffffffff8168e602>] vfs_ioctl fs/ioctl.c:51 [inline] > [<ffffffff8168e602>] __do_sys_ioctl fs/ioctl.c:870 [inline] > [<ffffffff8168e602>] __se_sys_ioctl fs/ioctl.c:856 [inline] > [<ffffffff8168e602>] __x64_sys_ioctl+0xf2/0x140 fs/ioctl.c:856 > [<ffffffff84ad2bb8>] do_syscall_x64 arch/x86/entry/common.c:50 > [inline] > [<ffffffff84ad2bb8>] do_syscall_64+0x38/0xb0 > arch/x86/entry/common.c:80 > [<ffffffff84c0008b>] entry_SYSCALL_64_after_hwframe+0x63/0xcd > > BUG: memory leak > unreferenced object 0xffff888109d2d800 (size 1024): > comm "syz-executor121", pid 5010, jiffies 4294944269 (age 7.320s) > hex dump (first 32 bytes): > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > backtrace: > [<ffffffff81554bbb>] __do_kmalloc_node mm/slab_common.c:984 > [inline] > [<ffffffff81554bbb>] __kmalloc_node+0x4b/0x150 mm/slab_common.c:992 > [<ffffffff815440f9>] kmalloc_node include/linux/slab.h:602 [inline] > [<ffffffff815440f9>] kvmalloc_node+0x99/0x170 mm/util.c:604 > [<ffffffff824c52fe>] kvmalloc include/linux/slab.h:720 [inline] > [<ffffffff824c52fe>] kvmalloc_array include/linux/slab.h:738 > [inline] > [<ffffffff824c52fe>] want_pages_array lib/iov_iter.c:985 [inline] > [<ffffffff824c52fe>] iov_iter_extract_user_pages > lib/iov_iter.c:1765 [inline] > [<ffffffff824c52fe>] iov_iter_extract_pages+0x1ee/0xa40 > lib/iov_iter.c:1831 > [<ffffffff824125a7>] bio_map_user_iov+0x167/0x5d0 > block/blk-map.c:297 > [<ffffffff82412df3>] blk_rq_map_user_iov+0x3e3/0xb30 > block/blk-map.c:664 > [<ffffffff82413943>] blk_rq_map_user block/blk-map.c:691 [inline] > [<ffffffff82413943>] blk_rq_map_user_io+0x143/0x160 > block/blk-map.c:724 > [<ffffffff82ca0925>] sg_io+0x285/0x510 > drivers/scsi/scsi_ioctl.c:456 > [<ffffffff82ca1025>] scsi_cdrom_send_packet+0x1b5/0x480 > drivers/scsi/scsi_ioctl.c:820 > [<ffffffff82ca13ba>] scsi_ioctl+0xca/0xd30 > drivers/scsi/scsi_ioctl.c:903 > [<ffffffff82d35964>] sg_ioctl+0x5f4/0x10a0 drivers/scsi/sg.c:1163 > [<ffffffff8168e602>] vfs_ioctl fs/ioctl.c:51 [inline] > [<ffffffff8168e602>] __do_sys_ioctl fs/ioctl.c:870 [inline] > [<ffffffff8168e602>] __se_sys_ioctl fs/ioctl.c:856 [inline] > [<ffffffff8168e602>] __x64_sys_ioctl+0xf2/0x140 fs/ioctl.c:856 > [<ffffffff84ad2bb8>] do_syscall_x64 arch/x86/entry/common.c:50 > [inline] > [<ffffffff84ad2bb8>] do_syscall_64+0x38/0xb0 > arch/x86/entry/common.c:80 > [<ffffffff84c0008b>] entry_SYSCALL_64_after_hwframe+0x63/0xcd > > Reported-by: syzbot+cb729843d0f42a5c1a50@syzkaller.appspotmail.com > Closes: > https://syzkaller.appspot.com/bug?id=99c8551967f413d108cfdd2950a0cb5652de07b8 > Fixes: 7d58fe7310281 ("iov_iter: Add a function to extract a page list > from an iterator") > Signed-off-by: José Pekkarinen <jose.pekkarinen@foxhound.fi> > --- > lib/iov_iter.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/lib/iov_iter.c b/lib/iov_iter.c > index 27234a820eeb..c3fd0448dead 100644 > --- a/lib/iov_iter.c > +++ b/lib/iov_iter.c > @@ -1780,8 +1780,10 @@ static ssize_t > iov_iter_extract_user_pages(struct iov_iter *i, > if (!maxpages) > return -ENOMEM; > res = pin_user_pages_fast(addr, maxpages, gup_flags, *pages); > - if (unlikely(res <= 0)) > + if (unlikely(res <= 0)) { > + kvfree(*pages); > return res; > + } > maxsize = min_t(size_t, maxsize, res * PAGE_SIZE - offset); > iov_iter_advance(i, maxsize); > return maxsize;
Ping.
José.
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