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e03101824d
Pavel Skripkin says:
====================
This patch series fix 2 memory leaks in caif
interface.
Syzbot reported memory leak in cfserl_create().
The problem was in cfcnfg_add_phy_layer() function.
This function accepts struct cflayer *link_support and
assign it to corresponting structures, but it can fail
in some cases.
These cases must be handled to prevent leaking allocated
struct cflayer *link_support pointer, because if error accured
before assigning link_support pointer to somewhere, this pointer
must be freed.
Fail log:
[ 49.051872][ T7010] caif:cfcnfg_add_phy_layer(): Too many CAIF Link Layers (max 6)
[ 49.110236][ T7042] caif:cfcnfg_add_phy_layer(): Too many CAIF Link Layers (max 6)
[ 49.134936][ T7045] caif:cfcnfg_add_phy_layer(): Too many CAIF Link Layers (max 6)
[ 49.163083][ T7043] caif:cfcnfg_add_phy_layer(): Too many CAIF Link Layers (max 6)
[ 55.248950][ T6994] kmemleak: 4 new suspected memory leaks (see /sys/kernel/debug/kmemleak)
int cfcnfg_add_phy_layer(..., struct cflayer *link_support, ...)
{
...
/* CAIF protocol allow maximum 6 link-layers */
for (i = 0; i < 7; i++) {
phyid = (dev->ifindex + i) & 0x7;
if (phyid == 0)
continue;
if (cfcnfg_get_phyinfo_rcu(cnfg, phyid) == NULL)
goto got_phyid;
}
pr_warn("Too many CAIF Link Layers (max 6)\n");
goto out;
...
if (link_support != NULL) {
link_support->id = phyid;
layer_set_dn(frml, link_support);
layer_set_up(link_support, frml);
layer_set_dn(link_support, phy_layer);
layer_set_up(phy_layer, link_support);
}
...
}
As you can see, if cfcnfg_add_phy_layer fails before layer_set_*,
link_support becomes leaked.
So, in this series, I made cfcnfg_add_phy_layer()
return an int and added error handling code to prevent
leaking link_support pointer in caif_device_notify()
and cfusbl_device_notify() functions.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Linux kernel
============
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In order to build the documentation, use ``make htmldocs`` or
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https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
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the problems which may result by upgrading your kernel.