* [PATCH] comedi: Fix memory leak in compat_insnlist()
@ 2021-09-16 14:44 Ian Abbott
2021-09-16 14:47 ` Ian Abbott
2021-09-16 14:50 ` [PATCH v2] " Ian Abbott
0 siblings, 2 replies; 3+ messages in thread
From: Ian Abbott @ 2021-09-16 14:44 UTC (permalink / raw)
To: linux-kernel
Cc: Ian Abbott, H Hartley Sweeten, Al Viro, Greg Kroah-Hartman,
linux-staging, stable
`compat_insnlist()` handles the 32-bit version of the `COMEDI_INSNLIST`
ioctl (whenwhen `CONFIG_COMPAT` is enabled). It allocates memory to
temporarily hold an array of `struct comedi_insn` converted from the
32-bit version in user space. This memory is only being freed if there
is a fault while filling the array, otherwise it is leaked.
Add a call to `kfree()` to fix the leak.
Fixes: b8d47d881305 ("comedi: get rid of compat_alloc_user_space() mess in COMEDI_INSNLIST compat"
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Greg Kroah-Hartman <greglh@linuxfoundation.org>
Cc: linux-staging@lists.linux.dev
Cc: <stable@vger.kernel.org> # 5.13+
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
---
N.B. Also need patches for 5.8+ from before comedi moved out of staging.
---
drivers/comedi/comedi_fops.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/comedi/comedi_fops.c b/drivers/comedi/comedi_fops.c
index df77b6bf5c64..763cea8418f8 100644
--- a/drivers/comedi/comedi_fops.c
+++ b/drivers/comedi/comedi_fops.c
@@ -3090,6 +3090,7 @@ static int compat_insnlist(struct file *file, unsigned long arg)
mutex_lock(&dev->mutex);
rc = do_insnlist_ioctl(dev, insns, insnlist32.n_insns, file);
mutex_unlock(&dev->mutex);
+ kfree(insns);
return rc;
}
--
2.33.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] comedi: Fix memory leak in compat_insnlist()
2021-09-16 14:44 [PATCH] comedi: Fix memory leak in compat_insnlist() Ian Abbott
@ 2021-09-16 14:47 ` Ian Abbott
2021-09-16 14:50 ` [PATCH v2] " Ian Abbott
1 sibling, 0 replies; 3+ messages in thread
From: Ian Abbott @ 2021-09-16 14:47 UTC (permalink / raw)
To: linux-kernel
Cc: H Hartley Sweeten, Al Viro, Greg Kroah-Hartman, linux-staging, stable
On 16/09/2021 15:44, Ian Abbott wrote:
> Cc: Greg Kroah-Hartman <greglh@linuxfoundation.org>
Sorry, I need to resend it to fix that typo.
--
-=( Ian Abbott <abbotti@mev.co.uk> || MEV Ltd. is a company )=-
-=( registered in England & Wales. Regd. number: 02862268. )=-
-=( Regd. addr.: S11 & 12 Building 67, Europa Business Park, )=-
-=( Bird Hall Lane, STOCKPORT, SK3 0XA, UK. || www.mev.co.uk )=-
^ permalink raw reply [flat|nested] 3+ messages in thread
* [PATCH v2] comedi: Fix memory leak in compat_insnlist()
2021-09-16 14:44 [PATCH] comedi: Fix memory leak in compat_insnlist() Ian Abbott
2021-09-16 14:47 ` Ian Abbott
@ 2021-09-16 14:50 ` Ian Abbott
1 sibling, 0 replies; 3+ messages in thread
From: Ian Abbott @ 2021-09-16 14:50 UTC (permalink / raw)
To: linux-kernel
Cc: Ian Abbott, H Hartley Sweeten, Al Viro, Greg Kroah-Hartman,
linux-staging, stable
`compat_insnlist()` handles the 32-bit version of the `COMEDI_INSNLIST`
ioctl (whenwhen `CONFIG_COMPAT` is enabled). It allocates memory to
temporarily hold an array of `struct comedi_insn` converted from the
32-bit version in user space. This memory is only being freed if there
is a fault while filling the array, otherwise it is leaked.
Add a call to `kfree()` to fix the leak.
Fixes: b8d47d881305 ("comedi: get rid of compat_alloc_user_space() mess in COMEDI_INSNLIST compat"
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-staging@lists.linux.dev
Cc: <stable@vger.kernel.org> # 5.13+
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
---
v2: Corrected typo in Greg's email address.
N.B. Also need patches for 5.8+ from before comedi moved out of staging.
---
drivers/comedi/comedi_fops.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/comedi/comedi_fops.c b/drivers/comedi/comedi_fops.c
index df77b6bf5c64..763cea8418f8 100644
--- a/drivers/comedi/comedi_fops.c
+++ b/drivers/comedi/comedi_fops.c
@@ -3090,6 +3090,7 @@ static int compat_insnlist(struct file *file, unsigned long arg)
mutex_lock(&dev->mutex);
rc = do_insnlist_ioctl(dev, insns, insnlist32.n_insns, file);
mutex_unlock(&dev->mutex);
+ kfree(insns);
return rc;
}
--
2.33.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
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