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author | Frank Rowand <frank.rowand@am.sony.com> | 2016-06-16 10:51:46 -0700 |
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committer | Rob Herring <robh@kernel.org> | 2016-06-24 15:16:10 -0500 |
commit | d9fc880723321dbf16b2981e3f3e916b73942210 (patch) | |
tree | 0e483dcd218e52726f6669f74f64e036eb9f9420 /drivers | |
parent | e1bcbee6f95301197e1039b4e4104cbdc4a332a6 (diff) | |
download | linux-d9fc880723321dbf16b2981e3f3e916b73942210.tar.gz linux-d9fc880723321dbf16b2981e3f3e916b73942210.tar.bz2 linux-d9fc880723321dbf16b2981e3f3e916b73942210.zip |
of: fix memory leak related to safe_name()
Fix a memory leak resulting from memory allocation in safe_name().
This patch fixes all call sites of safe_name().
Mathieu Malaterre reported the memory leak on boot:
On my PowerMac device-tree would generate a duplicate name:
[ 0.023043] device-tree: Duplicate name in PowerPC,G4@0, renamed to "l2-cache#1"
in this case a newly allocated name is generated by `safe_name`. However
in this case it is never deallocated.
The bug was found using kmemleak reported as:
unreferenced object 0xdf532e60 (size 32):
comm "swapper", pid 1, jiffies 4294892300 (age 1993.532s)
hex dump (first 32 bytes):
6c 32 2d 63 61 63 68 65 23 31 00 dd e4 dd 1e c2 l2-cache#1......
ec d4 ba ce 04 ec cc de 8e 85 e9 ca c4 ec cc 9e ................
backtrace:
[<c02d3350>] kvasprintf+0x64/0xc8
[<c02d3400>] kasprintf+0x4c/0x5c
[<c0453814>] safe_name.isra.1+0x80/0xc4
[<c04545d8>] __of_attach_node_sysfs+0x6c/0x11c
[<c075f21c>] of_core_init+0x8c/0xf8
[<c0729594>] kernel_init_freeable+0xd4/0x208
[<c00047e8>] kernel_init+0x24/0x11c
[<c00158ec>] ret_from_kernel_thread+0x5c/0x64
Link: https://bugzilla.kernel.org/show_bug.cgi?id=120331
Signed-off-by: Frank Rowand <frank.rowand@am.sony.com>
Reported-by: mathieu.malaterre@gmail.com
Tested-by: Mathieu Malaterre <mathieu.malaterre@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/of/base.c | 30 | ||||
-rw-r--r-- | drivers/of/dynamic.c | 2 | ||||
-rw-r--r-- | drivers/of/of_private.h | 3 |
3 files changed, 25 insertions, 10 deletions
diff --git a/drivers/of/base.c b/drivers/of/base.c index ebf84e3b56d5..8bb3d1adf1b0 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -112,6 +112,7 @@ static ssize_t of_node_property_read(struct file *filp, struct kobject *kobj, return memory_read_from_buffer(buf, count, &offset, pp->value, pp->length); } +/* always return newly allocated name, caller must free after use */ static const char *safe_name(struct kobject *kobj, const char *orig_name) { const char *name = orig_name; @@ -126,9 +127,12 @@ static const char *safe_name(struct kobject *kobj, const char *orig_name) name = kasprintf(GFP_KERNEL, "%s#%i", orig_name, ++i); } - if (name != orig_name) + if (name == orig_name) { + name = kstrdup(orig_name, GFP_KERNEL); + } else { pr_warn("device-tree: Duplicate name in %s, renamed to \"%s\"\n", kobject_name(kobj), name); + } return name; } @@ -159,6 +163,7 @@ int __of_add_property_sysfs(struct device_node *np, struct property *pp) int __of_attach_node_sysfs(struct device_node *np) { const char *name; + struct kobject *parent; struct property *pp; int rc; @@ -171,15 +176,16 @@ int __of_attach_node_sysfs(struct device_node *np) np->kobj.kset = of_kset; if (!np->parent) { /* Nodes without parents are new top level trees */ - rc = kobject_add(&np->kobj, NULL, "%s", - safe_name(&of_kset->kobj, "base")); + name = safe_name(&of_kset->kobj, "base"); + parent = NULL; } else { name = safe_name(&np->parent->kobj, kbasename(np->full_name)); - if (!name || !name[0]) - return -EINVAL; - - rc = kobject_add(&np->kobj, &np->parent->kobj, "%s", name); + parent = &np->parent->kobj; } + if (!name) + return -ENOMEM; + rc = kobject_add(&np->kobj, parent, "%s", name); + kfree(name); if (rc) return rc; @@ -1815,6 +1821,12 @@ int __of_remove_property(struct device_node *np, struct property *prop) return 0; } +void __of_sysfs_remove_bin_file(struct device_node *np, struct property *prop) +{ + sysfs_remove_bin_file(&np->kobj, &prop->attr); + kfree(prop->attr.attr.name); +} + void __of_remove_property_sysfs(struct device_node *np, struct property *prop) { if (!IS_ENABLED(CONFIG_SYSFS)) @@ -1822,7 +1834,7 @@ void __of_remove_property_sysfs(struct device_node *np, struct property *prop) /* at early boot, bail here and defer setup to of_init() */ if (of_kset && of_node_is_attached(np)) - sysfs_remove_bin_file(&np->kobj, &prop->attr); + __of_sysfs_remove_bin_file(np, prop); } /** @@ -1895,7 +1907,7 @@ void __of_update_property_sysfs(struct device_node *np, struct property *newprop return; if (oldprop) - sysfs_remove_bin_file(&np->kobj, &oldprop->attr); + __of_sysfs_remove_bin_file(np, oldprop); __of_add_property_sysfs(np, newprop); } diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c index 3033fa3250dc..a2015599ed7e 100644 --- a/drivers/of/dynamic.c +++ b/drivers/of/dynamic.c @@ -55,7 +55,7 @@ void __of_detach_node_sysfs(struct device_node *np) /* only remove properties if on sysfs */ if (of_node_is_attached(np)) { for_each_property_of_node(np, pp) - sysfs_remove_bin_file(&np->kobj, &pp->attr); + __of_sysfs_remove_bin_file(np, pp); kobject_del(&np->kobj); } diff --git a/drivers/of/of_private.h b/drivers/of/of_private.h index 829469faeb23..18bbb4517e25 100644 --- a/drivers/of/of_private.h +++ b/drivers/of/of_private.h @@ -83,6 +83,9 @@ extern int __of_attach_node_sysfs(struct device_node *np); extern void __of_detach_node(struct device_node *np); extern void __of_detach_node_sysfs(struct device_node *np); +extern void __of_sysfs_remove_bin_file(struct device_node *np, + struct property *prop); + /* iterators for transactions, used for overlays */ /* forward iterator */ #define for_each_transaction_entry(_oft, _te) \ |