[syzbot] [dri?] [media?] memory leak in get_sg_table

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: fbafc3e621c3 Merge tag 'for_linus' of git://git.kernel.org..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10ae11cee80000
kernel config: https://syzkaller.appspot.com/x/.config?x=e81921f96ae24ec0
dashboard link: https://syzkaller.appspot.com/bug?extid=9b4adfed366b14496e7e
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1635d436e80000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15e8171ae80000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/76e4a40f41aa/disk-fbafc3e6.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a2f88511ce98/vmlinux-fbafc3e6.xz
kernel image: https://storage.googleapis.com/syzbot-assets/2b21933ed8f1/bzImage-fbafc3e6.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9b4adf...@syzkaller.appspotmail.com

Warning: Permanently added '10.128.0.162' (ED25519) to the list of known hosts.
executing program
executing program
BUG: memory leak
unreferenced object 0xffff88810af03840 (size 16):
comm "syz-executor111", pid 5038, jiffies 4294942820 (age 13.250s)
hex dump (first 16 bytes):
80 8b 89 0b 81 88 ff ff 04 00 00 00 04 00 00 00 ................
backtrace:
[<ffffffff816346ed>] kmemleak_alloc_recursive include/linux/kmemleak.h:42 [inline]
[<ffffffff816346ed>] slab_post_alloc_hook mm/slab.h:766 [inline]
[<ffffffff816346ed>] slab_alloc_node mm/slub.c:3478 [inline]
[<ffffffff816346ed>] __kmem_cache_alloc_node+0x2dd/0x3f0 mm/slub.c:3517
[<ffffffff8157f315>] kmalloc_trace+0x25/0x90 mm/slab_common.c:1098
[<ffffffff82cfd7fa>] kmalloc include/linux/slab.h:600 [inline]
[<ffffffff82cfd7fa>] kzalloc include/linux/slab.h:721 [inline]
[<ffffffff82cfd7fa>] get_sg_table.isra.0+0x2a/0xe0 drivers/dma-buf/udmabuf.c:93
[<ffffffff82cfd943>] begin_cpu_udmabuf+0x63/0xa0 drivers/dma-buf/udmabuf.c:156
[<ffffffff82cf114b>] dma_buf_begin_cpu_access+0x3b/0xc0 drivers/dma-buf/dma-buf.c:1402
[<ffffffff82cf1d90>] dma_buf_ioctl+0x550/0x660 drivers/dma-buf/dma-buf.c:475
[<ffffffff816bf4a2>] vfs_ioctl fs/ioctl.c:51 [inline]
[<ffffffff816bf4a2>] __do_sys_ioctl fs/ioctl.c:871 [inline]
[<ffffffff816bf4a2>] __se_sys_ioctl fs/ioctl.c:857 [inline]
[<ffffffff816bf4a2>] __x64_sys_ioctl+0xf2/0x140 fs/ioctl.c:857
[<ffffffff84b71e2f>] do_syscall_x64 arch/x86/entry/common.c:52 [inline]
[<ffffffff84b71e2f>] do_syscall_64+0x3f/0x110 arch/x86/entry/common.c:83
[<ffffffff84c0008b>] entry_SYSCALL_64_after_hwframe+0x63/0x6b

BUG: memory leak
unreferenced object 0xffff88810b898b80 (size 128):
comm "syz-executor111", pid 5038, jiffies 4294942820 (age 13.250s)
hex dump (first 32 bytes):
c0 09 2a 04 00 ea ff ff 00 00 00 00 00 10 00 00 ..*.............
00 70 82 0a 01 00 00 00 00 10 00 00 00 00 00 00 .p..............
backtrace:
[<ffffffff816346ed>] kmemleak_alloc_recursive include/linux/kmemleak.h:42 [inline]
[<ffffffff816346ed>] slab_post_alloc_hook mm/slab.h:766 [inline]
[<ffffffff816346ed>] slab_alloc_node mm/slub.c:3478 [inline]
[<ffffffff816346ed>] __kmem_cache_alloc_node+0x2dd/0x3f0 mm/slub.c:3517
[<ffffffff8157f9bb>] __do_kmalloc_node mm/slab_common.c:1006 [inline]
[<ffffffff8157f9bb>] __kmalloc+0x4b/0x150 mm/slab_common.c:1020
[<ffffffff8251661f>] kmalloc_array include/linux/slab.h:637 [inline]
[<ffffffff8251661f>] sg_kmalloc lib/scatterlist.c:167 [inline]
[<ffffffff8251661f>] get_next_sg lib/scatterlist.c:402 [inline]
[<ffffffff8251661f>] sg_alloc_append_table_from_pages+0x35f/0x770 lib/scatterlist.c:526
[<ffffffff82516abc>] sg_alloc_table_from_pages_segment+0x8c/0x120 lib/scatterlist.c:586
[<ffffffff82cfd82e>] sg_alloc_table_from_pages include/linux/scatterlist.h:477 [inline]
[<ffffffff82cfd82e>] get_sg_table.isra.0+0x5e/0xe0 drivers/dma-buf/udmabuf.c:96
[<ffffffff82cfd943>] begin_cpu_udmabuf+0x63/0xa0 drivers/dma-buf/udmabuf.c:156
[<ffffffff82cf114b>] dma_buf_begin_cpu_access+0x3b/0xc0 drivers/dma-buf/dma-buf.c:1402
[<ffffffff82cf1d90>] dma_buf_ioctl+0x550/0x660 drivers/dma-buf/dma-buf.c:475
[<ffffffff816bf4a2>] vfs_ioctl fs/ioctl.c:51 [inline]
[<ffffffff816bf4a2>] __do_sys_ioctl fs/ioctl.c:871 [inline]
[<ffffffff816bf4a2>] __se_sys_ioctl fs/ioctl.c:857 [inline]
[<ffffffff816bf4a2>] __x64_sys_ioctl+0xf2/0x140 fs/ioctl.c:857
[<ffffffff84b71e2f>] do_syscall_x64 arch/x86/entry/common.c:52 [inline]
[<ffffffff84b71e2f>] do_syscall_64+0x3f/0x110 arch/x86/entry/common.c:83
[<ffffffff84c0008b>] entry_SYSCALL_64_after_hwframe+0x63/0x6b



---
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#syz undup

[Hillf Danton]

On Sun, 31 Dec 2023 15:38:19 -0800

> HEAD commit: fbafc3e621c3 Merge tag 'for_linus' of git://git.kernel.org..
> git tree: upstream

> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15e8171ae80000

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master

--- x/drivers/dma-buf/udmabuf.c
+++ y/drivers/dma-buf/udmabuf.c
@@ -153,7 +153,12 @@ static int begin_cpu_udmabuf(struct dma_
int ret = 0;

if (!ubuf->sg) {
- ubuf->sg = get_sg_table(dev, buf, direction);
+ static DEFINE_MUTEX(lock);
+
+ mutex_lock(&lock);
+ if (!ubuf->sg)
+ ubuf->sg = get_sg_table(dev, buf, direction);
+ mutex_unlock(&lock);
if (IS_ERR(ubuf->sg)) {
ret = PTR_ERR(ubuf->sg);
ubuf->sg = NULL;
--

[Edward Adam Davis]

please test memory leak in get_sg_table

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git fbafc3e621c3

diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index 21916bba77d5..709260211546 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -471,8 +471,11 @@ static long dma_buf_ioctl(struct file *file,

if (sync.flags & DMA_BUF_SYNC_END)
ret = dma_buf_end_cpu_access(dmabuf, direction);
- else
+ else {
+ if (dmabuf->doing)
+ return -EBUSY;
ret = dma_buf_begin_cpu_access(dmabuf, direction);
+ }

return ret;

diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c
index c40645999648..ed98c0319e03 100644
--- a/drivers/dma-buf/udmabuf.c
+++ b/drivers/dma-buf/udmabuf.c
@@ -152,6 +152,7 @@ static int begin_cpu_udmabuf(struct dma_buf *buf,
struct device *dev = ubuf->device->this_device;
int ret = 0;

+ buf->doing = true;
if (!ubuf->sg) {

ubuf->sg = get_sg_table(dev, buf, direction);

if (IS_ERR(ubuf->sg)) {
@@ -162,6 +163,7 @@ static int begin_cpu_udmabuf(struct dma_buf *buf,
dma_sync_sg_for_cpu(dev, ubuf->sg->sgl, ubuf->sg->nents,
direction);
}
+ buf->doing = false;

return ret;
}
diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h
index 3f31baa3293f..4316ad0e6155 100644
--- a/include/linux/dma-buf.h
+++ b/include/linux/dma-buf.h
@@ -446,6 +446,7 @@ struct dma_buf {
struct dma_buf *dmabuf;
} *sysfs_entry;
#endif
+ bool doing;
};

/**

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-and-tested-by: syzbot+9b4adf...@syzkaller.appspotmail.com

Tested on:

commit: 610a9b8f Linux 6.7-rc8
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
console output: https://syzkaller.appspot.com/x/log.txt?x=115abdd9e80000
kernel config: https://syzkaller.appspot.com/x/.config?x=dcb7609da8da79e3

dashboard link: https://syzkaller.appspot.com/bug?extid=9b4adfed366b14496e7e
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40

patch: https://syzkaller.appspot.com/x/patch.diff?x=12c685b5e80000

Note: testing is done by a robot and is best-effort only.

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
memory leak in get_sg_table

2024/01/01 02:58:28 executed programs: 1
BUG: memory leak
unreferenced object 0xffff88811b080600 (size 16):
comm "syz-executor.0", pid 5492, jiffies 4294944266 (age 13.620s)

hex dump (first 16 bytes):

80 22 25 1b 81 88 ff ff 04 00 00 00 04 00 00 00 ."%.............

backtrace:
[<ffffffff816346ed>] kmemleak_alloc_recursive include/linux/kmemleak.h:42 [inline]
[<ffffffff816346ed>] slab_post_alloc_hook mm/slab.h:766 [inline]
[<ffffffff816346ed>] slab_alloc_node mm/slub.c:3478 [inline]
[<ffffffff816346ed>] __kmem_cache_alloc_node+0x2dd/0x3f0 mm/slub.c:3517
[<ffffffff8157f315>] kmalloc_trace+0x25/0x90 mm/slab_common.c:1098

[<ffffffff82cfd82a>] kmalloc include/linux/slab.h:600 [inline]
[<ffffffff82cfd82a>] kzalloc include/linux/slab.h:721 [inline]
[<ffffffff82cfd82a>] get_sg_table.isra.0+0x2a/0xe0 drivers/dma-buf/udmabuf.c:93
[<ffffffff82cfd986>] begin_cpu_udmabuf+0x76/0xb0 drivers/dma-buf/udmabuf.c:157
[<ffffffff82cf114b>] dma_buf_begin_cpu_access+0x3b/0xc0 drivers/dma-buf/dma-buf.c:1405
[<ffffffff82cf1bd4>] dma_buf_ioctl+0x394/0x690 drivers/dma-buf/dma-buf.c:477

[<ffffffff816bf4a2>] vfs_ioctl fs/ioctl.c:51 [inline]
[<ffffffff816bf4a2>] __do_sys_ioctl fs/ioctl.c:871 [inline]
[<ffffffff816bf4a2>] __se_sys_ioctl fs/ioctl.c:857 [inline]
[<ffffffff816bf4a2>] __x64_sys_ioctl+0xf2/0x140 fs/ioctl.c:857
[<ffffffff84b71e2f>] do_syscall_x64 arch/x86/entry/common.c:52 [inline]
[<ffffffff84b71e2f>] do_syscall_64+0x3f/0x110 arch/x86/entry/common.c:83
[<ffffffff84c0008b>] entry_SYSCALL_64_after_hwframe+0x63/0x6b

BUG: memory leak

unreferenced object 0xffff88811b252280 (size 128):
comm "syz-executor.0", pid 5492, jiffies 4294944266 (age 13.620s)

hex dump (first 32 bytes):

00 b1 52 04 00 ea ff ff 00 00 00 00 00 10 00 00 ..R.............
00 40 ac 14 01 00 00 00 00 10 00 00 00 00 00 00 .@..............

backtrace:
[<ffffffff816346ed>] kmemleak_alloc_recursive include/linux/kmemleak.h:42 [inline]
[<ffffffff816346ed>] slab_post_alloc_hook mm/slab.h:766 [inline]
[<ffffffff816346ed>] slab_alloc_node mm/slub.c:3478 [inline]
[<ffffffff816346ed>] __kmem_cache_alloc_node+0x2dd/0x3f0 mm/slub.c:3517
[<ffffffff8157f9bb>] __do_kmalloc_node mm/slab_common.c:1006 [inline]
[<ffffffff8157f9bb>] __kmalloc+0x4b/0x150 mm/slab_common.c:1020
[<ffffffff8251661f>] kmalloc_array include/linux/slab.h:637 [inline]
[<ffffffff8251661f>] sg_kmalloc lib/scatterlist.c:167 [inline]
[<ffffffff8251661f>] get_next_sg lib/scatterlist.c:402 [inline]
[<ffffffff8251661f>] sg_alloc_append_table_from_pages+0x35f/0x770 lib/scatterlist.c:526
[<ffffffff82516abc>] sg_alloc_table_from_pages_segment+0x8c/0x120 lib/scatterlist.c:586

[<ffffffff82cfd85e>] sg_alloc_table_from_pages include/linux/scatterlist.h:477 [inline]
[<ffffffff82cfd85e>] get_sg_table.isra.0+0x5e/0xe0 drivers/dma-buf/udmabuf.c:96
[<ffffffff82cfd986>] begin_cpu_udmabuf+0x76/0xb0 drivers/dma-buf/udmabuf.c:157
[<ffffffff82cf114b>] dma_buf_begin_cpu_access+0x3b/0xc0 drivers/dma-buf/dma-buf.c:1405
[<ffffffff82cf1bd4>] dma_buf_ioctl+0x394/0x690 drivers/dma-buf/dma-buf.c:477

[<ffffffff816bf4a2>] vfs_ioctl fs/ioctl.c:51 [inline]
[<ffffffff816bf4a2>] __do_sys_ioctl fs/ioctl.c:871 [inline]
[<ffffffff816bf4a2>] __se_sys_ioctl fs/ioctl.c:857 [inline]
[<ffffffff816bf4a2>] __x64_sys_ioctl+0xf2/0x140 fs/ioctl.c:857
[<ffffffff84b71e2f>] do_syscall_x64 arch/x86/entry/common.c:52 [inline]
[<ffffffff84b71e2f>] do_syscall_64+0x3f/0x110 arch/x86/entry/common.c:83
[<ffffffff84c0008b>] entry_SYSCALL_64_after_hwframe+0x63/0x6b

Tested on:

commit: fbafc3e6 Merge tag 'for_linus' of git://git.kernel.org..
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=13cf2909e80000
kernel config: https://syzkaller.appspot.com/x/.config?x=e81921f96ae24ec0

dashboard link: https://syzkaller.appspot.com/bug?extid=9b4adfed366b14496e7e
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40

patch: https://syzkaller.appspot.com/x/patch.diff?x=14778665e80000

[Edward Adam Davis]

please test memory leak in get_sg_table

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git fbafc3e621c3

diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index 21916bba77d5..709260211546 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -471,8 +471,11 @@ static long dma_buf_ioctl(struct file *file,

if (sync.flags & DMA_BUF_SYNC_END)
ret = dma_buf_end_cpu_access(dmabuf, direction);
- else
+ else {
+ if (dmabuf->doing)
+ return -EBUSY;
ret = dma_buf_begin_cpu_access(dmabuf, direction);
+ }

return ret;

diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c

index c40645999648..ff49e5cf7d07 100644
--- a/drivers/dma-buf/udmabuf.c
+++ b/drivers/dma-buf/udmabuf.c
@@ -151,7 +151,10 @@ static int begin_cpu_udmabuf(struct dma_buf *buf,
struct udmabuf *ubuf = buf->priv;

struct device *dev = ubuf->device->this_device;
int ret = 0;

+ static DEFINE_MUTEX(lock);

+ mutex_lock(&lock);

+ buf->doing = true;
if (!ubuf->sg) {
ubuf->sg = get_sg_table(dev, buf, direction);
if (IS_ERR(ubuf->sg)) {

@@ -162,6 +165,8 @@ static int begin_cpu_udmabuf(struct dma_buf *buf,

dma_sync_sg_for_cpu(dev, ubuf->sg->sgl, ubuf->sg->nents,
direction);
}
+ buf->doing = false;

+ mutex_unlock(&lock);

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-and-tested-by: syzbot+9b4adf...@syzkaller.appspotmail.com

Tested on:

commit: fbafc3e6 Merge tag 'for_linus' of git://git.kernel.org..
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git

console output: https://syzkaller.appspot.com/x/log.txt?x=103d8899e80000

kernel config: https://syzkaller.appspot.com/x/.config?x=e81921f96ae24ec0
dashboard link: https://syzkaller.appspot.com/bug?extid=9b4adfed366b14496e7e
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40

patch: https://syzkaller.appspot.com/x/patch.diff?x=113c3829e80000