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author | Eric Biggers <ebiggers@google.com> | 2019-10-14 14:11:54 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-10-14 15:04:00 -0700 |
commit | 3c52b0af059e11a063970aed1ad143b9284a79c7 (patch) | |
tree | 3932cc5533532bd7a3398aa9d18413c68f1b4a29 /lib | |
parent | e4f8e513c3d353c134ad4eef9fd0bba12406c7c8 (diff) | |
download | linux-3c52b0af059e11a063970aed1ad143b9284a79c7.tar.bz2 |
lib/generic-radix-tree.c: add kmemleak annotations
Kmemleak is falsely reporting a leak of the slab allocation in
sctp_stream_init_ext():
BUG: memory leak
unreferenced object 0xffff8881114f5d80 (size 96):
comm "syz-executor934", pid 7160, jiffies 4294993058 (age 31.950s)
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:
[<00000000ce7a1326>] kmemleak_alloc_recursive include/linux/kmemleak.h:55 [inline]
[<00000000ce7a1326>] slab_post_alloc_hook mm/slab.h:439 [inline]
[<00000000ce7a1326>] slab_alloc mm/slab.c:3326 [inline]
[<00000000ce7a1326>] kmem_cache_alloc_trace+0x13d/0x280 mm/slab.c:3553
[<000000007abb7ac9>] kmalloc include/linux/slab.h:547 [inline]
[<000000007abb7ac9>] kzalloc include/linux/slab.h:742 [inline]
[<000000007abb7ac9>] sctp_stream_init_ext+0x2b/0xa0 net/sctp/stream.c:157
[<0000000048ecb9c1>] sctp_sendmsg_to_asoc+0x946/0xa00 net/sctp/socket.c:1882
[<000000004483ca2b>] sctp_sendmsg+0x2a8/0x990 net/sctp/socket.c:2102
[...]
But it's freed later. Kmemleak misses the allocation because its
pointer is stored in the generic radix tree sctp_stream::out, and the
generic radix tree uses raw pages which aren't tracked by kmemleak.
Fix this by adding the kmemleak hooks to the generic radix tree code.
Link: http://lkml.kernel.org/r/20191004065039.727564-1-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reported-by: <syzbot+7f3b6b106be8dcdcdeec@syzkaller.appspotmail.com>
Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Vlad Yasevich <vyasevich@gmail.com>
Cc: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib')
-rw-r--r-- | lib/generic-radix-tree.c | 32 |
1 files changed, 26 insertions, 6 deletions
diff --git a/lib/generic-radix-tree.c b/lib/generic-radix-tree.c index ae25e2fa2187..f25eb111c051 100644 --- a/lib/generic-radix-tree.c +++ b/lib/generic-radix-tree.c @@ -2,6 +2,7 @@ #include <linux/export.h> #include <linux/generic-radix-tree.h> #include <linux/gfp.h> +#include <linux/kmemleak.h> #define GENRADIX_ARY (PAGE_SIZE / sizeof(struct genradix_node *)) #define GENRADIX_ARY_SHIFT ilog2(GENRADIX_ARY) @@ -75,6 +76,27 @@ void *__genradix_ptr(struct __genradix *radix, size_t offset) } EXPORT_SYMBOL(__genradix_ptr); +static inline struct genradix_node *genradix_alloc_node(gfp_t gfp_mask) +{ + struct genradix_node *node; + + node = (struct genradix_node *)__get_free_page(gfp_mask|__GFP_ZERO); + + /* + * We're using pages (not slab allocations) directly for kernel data + * structures, so we need to explicitly inform kmemleak of them in order + * to avoid false positive memory leak reports. + */ + kmemleak_alloc(node, PAGE_SIZE, 1, gfp_mask); + return node; +} + +static inline void genradix_free_node(struct genradix_node *node) +{ + kmemleak_free(node); + free_page((unsigned long)node); +} + /* * Returns pointer to the specified byte @offset within @radix, allocating it if * necessary - newly allocated slots are always zeroed out: @@ -97,8 +119,7 @@ void *__genradix_ptr_alloc(struct __genradix *radix, size_t offset, break; if (!new_node) { - new_node = (void *) - __get_free_page(gfp_mask|__GFP_ZERO); + new_node = genradix_alloc_node(gfp_mask); if (!new_node) return NULL; } @@ -121,8 +142,7 @@ void *__genradix_ptr_alloc(struct __genradix *radix, size_t offset, n = READ_ONCE(*p); if (!n) { if (!new_node) { - new_node = (void *) - __get_free_page(gfp_mask|__GFP_ZERO); + new_node = genradix_alloc_node(gfp_mask); if (!new_node) return NULL; } @@ -133,7 +153,7 @@ void *__genradix_ptr_alloc(struct __genradix *radix, size_t offset, } if (new_node) - free_page((unsigned long) new_node); + genradix_free_node(new_node); return &n->data[offset]; } @@ -191,7 +211,7 @@ static void genradix_free_recurse(struct genradix_node *n, unsigned level) genradix_free_recurse(n->children[i], level - 1); } - free_page((unsigned long) n); + genradix_free_node(n); } int __genradix_prealloc(struct __genradix *radix, size_t size, |