Re: memory leak in crypto_create_tfm

Eric Biggers
2020-06-03T03:55:45Z

Probably a bug in crypto/drbg.c. Stephan, can you take a look?

On Tue, Jun 02, 2020 at 08:41:21PM -0700, syzbot wrote:
> Hello,
>
> syzbot found the following crash on:
>
> HEAD commit: 19409891 Merge tag 'pnp-5.8-rc1' of git://git.kernel.org/p..
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=13165aa6100000
> kernel config: https://syzkaller.appspot.com/x/.config?x=6d41e63a2c7e0715
> dashboard link: https://syzkaller.appspot.com/bug?extid=2e635807decef724a1fa
> compiler: gcc (GCC) 9.0.0 20181231 (experimental)
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17f00ef2100000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=170f2ef2100000
>
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+2e635807decef724a1fa@syzkaller.appspotmail.com
>
> executing program
> executing program
> BUG: memory leak
> unreferenced object 0xffff8881175bc480 (size 64):
> comm "syz-executor064", pid 6388, jiffies 4294941622 (age 13.280s)
> hex dump (first 32 bytes):
> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
> e0 7e 56 84 ff ff ff ff 00 00 00 00 00 00 00 00 .~V.............
> backtrace:
> [<0000000029c7602f>] kmalloc include/linux/slab.h:560 [inline]
> [<0000000029c7602f>] kzalloc include/linux/slab.h:669 [inline]
> [<0000000029c7602f>] crypto_create_tfm+0x31/0x100 crypto/api.c:448
> [<00000000bec8cbdb>] crypto_alloc_tfm+0x79/0x1a0 crypto/api.c:527
> [<000000002f9791ba>] drbg_prepare_hrng crypto/drbg.c:1509 [inline]
> [<000000002f9791ba>] drbg_instantiate crypto/drbg.c:1587 [inline]
> [<000000002f9791ba>] drbg_kcapi_seed+0x432/0x6a9 crypto/drbg.c:1980
> [<0000000041302bb8>] crypto_rng_reset+0x35/0x1a0 crypto/rng.c:53
> [<000000004758c3c4>] alg_setkey crypto/af_alg.c:222 [inline]
> [<000000004758c3c4>] alg_setsockopt+0x149/0x190 crypto/af_alg.c:255
> [<000000008bc4b5cb>] __sys_setsockopt+0x112/0x230 net/socket.c:2132
> [<00000000cfbf30da>] __do_sys_setsockopt net/socket.c:2148 [inline]
> [<00000000cfbf30da>] __se_sys_setsockopt net/socket.c:2145 [inline]
> [<00000000cfbf30da>] __x64_sys_setsockopt+0x22/0x30 net/socket.c:2145
> [<00000000fc9c2183>] do_syscall_64+0x6e/0x220 arch/x86/entry/common.c:295
> [<0000000040e080a1>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
>
> BUG: memory leak
> unreferenced object 0xffff8881175bc040 (size 64):
> comm "syz-executor064", pid 6389, jiffies 4294942172 (age 7.780s)
> hex dump (first 32 bytes):
> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
> e0 7e 56 84 ff ff ff ff 00 00 00 00 00 00 00 00 .~V.............
> backtrace:
> [<0000000029c7602f>] kmalloc include/linux/slab.h:560 [inline]
> [<0000000029c7602f>] kzalloc include/linux/slab.h:669 [inline]
> [<0000000029c7602f>] crypto_create_tfm+0x31/0x100 crypto/api.c:448
> [<00000000bec8cbdb>] crypto_alloc_tfm+0x79/0x1a0 crypto/api.c:527
> [<000000002f9791ba>] drbg_prepare_hrng crypto/drbg.c:1509 [inline]
> [<000000002f9791ba>] drbg_instantiate crypto/drbg.c:1587 [inline]
> [<000000002f9791ba>] drbg_kcapi_seed+0x432/0x6a9 crypto/drbg.c:1980
> [<0000000041302bb8>] crypto_rng_reset+0x35/0x1a0 crypto/rng.c:53
> [<000000004758c3c4>] alg_setkey crypto/af_alg.c:222 [inline]
> [<000000004758c3c4>] alg_setsockopt+0x149/0x190 crypto/af_alg.c:255
> [<000000008bc4b5cb>] __sys_setsockopt+0x112/0x230 net/socket.c:2132
> [<00000000cfbf30da>] __do_sys_setsockopt net/socket.c:2148 [inline]
> [<00000000cfbf30da>] __se_sys_setsockopt net/socket.c:2145 [inline]
> [<00000000cfbf30da>] __x64_sys_setsockopt+0x22/0x30 net/socket.c:2145
> [<00000000fc9c2183>] do_syscall_64+0x6e/0x220 arch/x86/entry/common.c:295
> [<0000000040e080a1>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
>
> BUG: memory leak
> unreferenced object 0xffff88811b3ca080 (size 96):
> comm "syz-executor064", pid 6389, jiffies 4294942172 (age 7.780s)
> hex dump (first 32 bytes):
> 89 c7 08 cb 8a 12 10 6e 00 00 00 00 00 00 00 00 .......n........
> 71 51 5a c2 1b 00 00 00 35 7d 00 00 00 00 00 00 qQZ.....5}......
> backtrace:
> [<000000008ec3eca0>] jent_entropy_collector_alloc+0x1b/0xf8 crypto/jitterentropy.c:662
> [<0000000026ed401a>] jent_kcapi_init+0x17/0x40 crypto/jitterentropy-kcapi.c:119
> [<00000000be7d6b06>] crypto_create_tfm+0x89/0x100 crypto/api.c:459
> [<00000000bec8cbdb>] crypto_alloc_tfm+0x79/0x1a0 crypto/api.c:527
> [<000000002f9791ba>] drbg_prepare_hrng crypto/drbg.c:1509 [inline]
> [<000000002f9791ba>] drbg_instantiate crypto/drbg.c:1587 [inline]
> [<000000002f9791ba>] drbg_kcapi_seed+0x432/0x6a9 crypto/drbg.c:1980
> [<0000000041302bb8>] crypto_rng_reset+0x35/0x1a0 crypto/rng.c:53
> [<000000004758c3c4>] alg_setkey crypto/af_alg.c:222 [inline]
> [<000000004758c3c4>] alg_setsockopt+0x149/0x190 crypto/af_alg.c:255
> [<000000008bc4b5cb>] __sys_setsockopt+0x112/0x230 net/socket.c:2132
> [<00000000cfbf30da>] __do_sys_setsockopt net/socket.c:2148 [inline]
> [<00000000cfbf30da>] __se_sys_setsockopt net/socket.c:2145 [inline]
> [<00000000cfbf30da>] __x64_sys_setsockopt+0x22/0x30 net/socket.c:2145
> [<00000000fc9c2183>] do_syscall_64+0x6e/0x220 arch/x86/entry/common.c:295
> [<0000000040e080a1>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
>
>
>
> ---
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